contestId int64 0 1.01k | name stringlengths 2 58 | tags listlengths 0 11 | title stringclasses 523
values | time-limit stringclasses 8
values | memory-limit stringclasses 8
values | problem-description stringlengths 0 7.15k | input-specification stringlengths 0 2.05k | output-specification stringlengths 0 1.5k | demo-input listlengths 0 7 | demo-output listlengths 0 7 | note stringlengths 0 5.24k | test_cases listlengths 0 402 | timeConsumedMillis int64 0 8k | memoryConsumedBytes int64 0 537M | score float64 -1 3.99 | __index_level_0__ int64 0 621k |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
120 | Winnie-the-Pooh and honey | [
"implementation",
"math"
] | null | null | As we all know, Winnie-the-Pooh just adores honey. Ones he and the Piglet found out that the Rabbit has recently gotten hold of an impressive amount of this sweet and healthy snack. As you may guess, Winnie and the Piglet asked to come at the Rabbit's place. Thus, there are *n* jars of honey lined up in front of Winnie-the-Pooh, jar number *i* contains *a**i* kilos of honey. Winnie-the-Pooh eats the honey like that: each time he chooses a jar containing most honey. If the jar has less that *k* kilos of honey or if Winnie-the-Pooh has already eaten from it three times, he gives the jar to Piglet. Otherwise he eats exactly *k* kilos of honey from the jar and puts it back. Winnie does so until he gives all jars to the Piglet. Count how much honey Piglet will overall get after Winnie satisfies his hunger. | The first line contains two integers *n* and *k* (1<=≤<=*n*<=≤<=100,<=1<=≤<=*k*<=≤<=100). The second line contains *n* integers *a*1, *a*2, ..., *a**n*, separated by spaces (1<=≤<=*a**i*<=≤<=100). | Print a single number — how many kilos of honey gets Piglet. | [
"3 3\n15 8 10\n"
] | [
"9\n"
] | none | [
{
"input": "3 3\n15 8 10",
"output": "9"
},
{
"input": "1 3\n3",
"output": "0"
},
{
"input": "3 4\n3 8 2",
"output": "5"
},
{
"input": "3 2\n95 25 49",
"output": "151"
},
{
"input": "3 1\n8 3 2",
"output": "5"
},
{
"input": "5 1\n4 7 9 5 7",
"outpu... | 218 | 0 | 3 | 726 | |
120 | Elevator | [
"brute force",
"implementation",
"math"
] | null | null | A sky scraper with 1000 floors has been built in the city of N. It has modern superfast elevators to help to travel from one floor to another. Each elevator has two doors, the front one and the back one. If one goes in through the front door, he goes out through the back one and vice versa. The elevator has two rails numbered with numbers 1 and 2. Rail 1 is located to the left of the entrance to the front door (or correspondingly, to the right of the entrance to the back door). Rail 2 is located opposite it, to the right of the entrance to the front door and to the left of the entrance to the back door. We know that each person in the city of N holds at a rail with the strongest hand.
One day a VIP person visited the city and of course, he took a look at the skyscraper and took a ride in the elevator. We know the door through which he entered and the rail he was holding at. Now we need to determine as soon as possible whether he is left-handed or right-handed. | The first line indicates the door through which the very important person entered the elevator. It contains "front" if the person enters the elevator through the front door and "back" if he entered the elevator through the back door. The second line contains integer *a* (1<=≤<=*a*<=≤<=2) which denotes the number of the rail at which the person was holding. | Print character "R" if the VIP is right-handed or "L" if he is left-handed. | [
"front\n1\n"
] | [
"L\n"
] | none | [
{
"input": "front\n1",
"output": "L"
},
{
"input": "back\n1",
"output": "R"
},
{
"input": "front\n2",
"output": "R"
},
{
"input": "back\n2",
"output": "L"
}
] | 216 | 0 | 0 | 727 | |
903 | The Modcrab | [
"greedy",
"implementation"
] | null | null | Vova is again playing some computer game, now an RPG. In the game Vova's character received a quest: to slay the fearsome monster called Modcrab.
After two hours of playing the game Vova has tracked the monster and analyzed its tactics. The Modcrab has *h*2 health points and an attack power of *a*2. Knowing that, Vova has decided to buy a lot of strong healing potions and to prepare for battle.
Vova's character has *h*1 health points and an attack power of *a*1. Also he has a large supply of healing potions, each of which increases his current amount of health points by *c*1 when Vova drinks a potion. All potions are identical to each other. It is guaranteed that *c*1<=><=*a*2.
The battle consists of multiple phases. In the beginning of each phase, Vova can either attack the monster (thus reducing its health by *a*1) or drink a healing potion (it increases Vova's health by *c*1; Vova's health can exceed *h*1). Then, if the battle is not over yet, the Modcrab attacks Vova, reducing his health by *a*2. The battle ends when Vova's (or Modcrab's) health drops to 0 or lower. It is possible that the battle ends in a middle of a phase after Vova's attack.
Of course, Vova wants to win the fight. But also he wants to do it as fast as possible. So he wants to make up a strategy that will allow him to win the fight after the minimum possible number of phases.
Help Vova to make up a strategy! You may assume that Vova never runs out of healing potions, and that he can always win. | The first line contains three integers *h*1, *a*1, *c*1 (1<=≤<=*h*1,<=*a*1<=≤<=100, 2<=≤<=*c*1<=≤<=100) — Vova's health, Vova's attack power and the healing power of a potion.
The second line contains two integers *h*2, *a*2 (1<=≤<=*h*2<=≤<=100, 1<=≤<=*a*2<=<<=*c*1) — the Modcrab's health and his attack power. | In the first line print one integer *n* denoting the minimum number of phases required to win the battle.
Then print *n* lines. *i*-th line must be equal to HEAL if Vova drinks a potion in *i*-th phase, or STRIKE if he attacks the Modcrab.
The strategy must be valid: Vova's character must not be defeated before slaying the Modcrab, and the monster's health must be 0 or lower after Vova's last action.
If there are multiple optimal solutions, print any of them. | [
"10 6 100\n17 5\n",
"11 6 100\n12 5\n"
] | [
"4\nSTRIKE\nHEAL\nSTRIKE\nSTRIKE\n",
"2\nSTRIKE\nSTRIKE\n"
] | In the first example Vova's character must heal before or after his first attack. Otherwise his health will drop to zero in 2 phases while he needs 3 strikes to win.
In the second example no healing needed, two strikes are enough to get monster to zero health and win with 6 health left. | [
{
"input": "10 6 100\n17 5",
"output": "4\nSTRIKE\nHEAL\nSTRIKE\nSTRIKE"
},
{
"input": "11 6 100\n12 5",
"output": "2\nSTRIKE\nSTRIKE"
},
{
"input": "25 27 91\n10 87",
"output": "1\nSTRIKE"
},
{
"input": "79 4 68\n9 65",
"output": "21\nSTRIKE\nHEAL\nHEAL\nHEAL\nHEAL\nHEAL... | 140 | 0 | 0 | 728 | |
567 | Lineland Mail | [
"greedy",
"implementation"
] | null | null | All cities of Lineland are located on the *Ox* coordinate axis. Thus, each city is associated with its position *x**i* — a coordinate on the *Ox* axis. No two cities are located at a single point.
Lineland residents love to send letters to each other. A person may send a letter only if the recipient lives in another city (because if they live in the same city, then it is easier to drop in).
Strange but true, the cost of sending the letter is exactly equal to the distance between the sender's city and the recipient's city.
For each city calculate two values *min**i* and *max**i*, where *min**i* is the minimum cost of sending a letter from the *i*-th city to some other city, and *max**i* is the the maximum cost of sending a letter from the *i*-th city to some other city | The first line of the input contains integer *n* (2<=≤<=*n*<=≤<=105) — the number of cities in Lineland. The second line contains the sequence of *n* distinct integers *x*1,<=*x*2,<=...,<=*x**n* (<=-<=109<=≤<=*x**i*<=≤<=109), where *x**i* is the *x*-coordinate of the *i*-th city. All the *x**i*'s are distinct and follow in ascending order. | Print *n* lines, the *i*-th line must contain two integers *min**i*,<=*max**i*, separated by a space, where *min**i* is the minimum cost of sending a letter from the *i*-th city, and *max**i* is the maximum cost of sending a letter from the *i*-th city. | [
"4\n-5 -2 2 7\n",
"2\n-1 1\n"
] | [
"3 12\n3 9\n4 7\n5 12\n",
"2 2\n2 2\n"
] | none | [
{
"input": "4\n-5 -2 2 7",
"output": "3 12\n3 9\n4 7\n5 12"
},
{
"input": "2\n-1 1",
"output": "2 2\n2 2"
},
{
"input": "3\n-1 0 1",
"output": "1 2\n1 1\n1 2"
},
{
"input": "4\n-1 0 1 3",
"output": "1 4\n1 3\n1 2\n2 4"
},
{
"input": "3\n-1000000000 0 1000000000",
... | 499 | 8,601,600 | 3 | 730 | |
159 | String Manipulation 1.0 | [
"*special",
"binary search",
"brute force",
"data structures",
"strings"
] | null | null | One popular website developed an unusual username editing procedure. One can change the username only by deleting some characters from it: to change the current name *s*, a user can pick number *p* and character *c* and delete the *p*-th occurrence of character *c* from the name. After the user changed his name, he can't undo the change.
For example, one can change name "arca" by removing the second occurrence of character "a" to get "arc".
Polycarpus learned that some user initially registered under nickname *t*, where *t* is a concatenation of *k* copies of string *s*. Also, Polycarpus knows the sequence of this user's name changes. Help Polycarpus figure out the user's final name. | The first line contains an integer *k* (1<=≤<=*k*<=≤<=2000). The second line contains a non-empty string *s*, consisting of lowercase Latin letters, at most 100 characters long. The third line contains an integer *n* (0<=≤<=*n*<=≤<=20000) — the number of username changes. Each of the next *n* lines contains the actual changes, one per line. The changes are written as "*p**i* *c**i*" (without the quotes), where *p**i* (1<=≤<=*p**i*<=≤<=200000) is the number of occurrences of letter *c**i*, *c**i* is a lowercase Latin letter. It is guaranteed that the operations are correct, that is, the letter to be deleted always exists, and after all operations not all letters are deleted from the name. The letters' occurrences are numbered starting from 1. | Print a single string — the user's final name after all changes are applied to it. | [
"2\nbac\n3\n2 a\n1 b\n2 c\n",
"1\nabacaba\n4\n1 a\n1 a\n1 c\n2 b\n"
] | [
"acb\n",
"baa\n"
] | Let's consider the first sample. Initially we have name "bacbac"; the first operation transforms it into "bacbc", the second one — to "acbc", and finally, the third one transforms it into "acb". | [
{
"input": "2\nbac\n3\n2 a\n1 b\n2 c",
"output": "acb"
},
{
"input": "1\nabacaba\n4\n1 a\n1 a\n1 c\n2 b",
"output": "baa"
},
{
"input": "1\naabbabbb\n7\n2 a\n1 a\n1 a\n2 b\n1 b\n3 b\n1 b",
"output": "b"
},
{
"input": "1\na\n0",
"output": "a"
},
{
"input": "4\ndb\n... | 2,806 | 12,800,000 | 3 | 732 | |
0 | none | [
"none"
] | null | null | Kyoya Ootori has a bag with *n* colored balls that are colored with *k* different colors. The colors are labeled from 1 to *k*. Balls of the same color are indistinguishable. He draws balls from the bag one by one until the bag is empty. He noticed that he drew the last ball of color *i* before drawing the last ball of color *i*<=+<=1 for all *i* from 1 to *k*<=-<=1. Now he wonders how many different ways this can happen. | The first line of input will have one integer *k* (1<=≤<=*k*<=≤<=1000) the number of colors.
Then, *k* lines will follow. The *i*-th line will contain *c**i*, the number of balls of the *i*-th color (1<=≤<=*c**i*<=≤<=1000).
The total number of balls doesn't exceed 1000. | A single integer, the number of ways that Kyoya can draw the balls from the bag as described in the statement, modulo 1<=000<=000<=007. | [
"3\n2\n2\n1\n",
"4\n1\n2\n3\n4\n"
] | [
"3\n",
"1680\n"
] | In the first sample, we have 2 balls of color 1, 2 balls of color 2, and 1 ball of color 3. The three ways for Kyoya are: | [
{
"input": "3\n2\n2\n1",
"output": "3"
},
{
"input": "4\n1\n2\n3\n4",
"output": "1680"
},
{
"input": "10\n100\n100\n100\n100\n100\n100\n100\n100\n100\n100",
"output": "12520708"
},
{
"input": "5\n10\n10\n10\n10\n10",
"output": "425711769"
},
{
"input": "11\n291\n3... | 202 | 2,662,400 | -1 | 734 | |
988 | Divisibility by 25 | [
"brute force",
"greedy"
] | null | null | You are given an integer $n$ from $1$ to $10^{18}$ without leading zeroes.
In one move you can swap any two adjacent digits in the given number in such a way that the resulting number will not contain leading zeroes. In other words, after each move the number you have cannot contain any leading zeroes.
What is the minimum number of moves you have to make to obtain a number that is divisible by $25$? Print -1 if it is impossible to obtain a number that is divisible by $25$. | The first line contains an integer $n$ ($1 \le n \le 10^{18}$). It is guaranteed that the first (left) digit of the number $n$ is not a zero. | If it is impossible to obtain a number that is divisible by $25$, print -1. Otherwise print the minimum number of moves required to obtain such number.
Note that you can swap only adjacent digits in the given number. | [
"5071\n",
"705\n",
"1241367\n"
] | [
"4\n",
"1\n",
"-1\n"
] | In the first example one of the possible sequences of moves is 5071 $\rightarrow$ 5701 $\rightarrow$ 7501 $\rightarrow$ 7510 $\rightarrow$ 7150. | [
{
"input": "5071",
"output": "4"
},
{
"input": "705",
"output": "1"
},
{
"input": "1241367",
"output": "-1"
},
{
"input": "7501",
"output": "2"
},
{
"input": "507",
"output": "2"
},
{
"input": "17010",
"output": "1"
},
{
"input": "52231",
... | 62 | 2,764,800 | 0 | 737 | |
11 | Increasing Sequence | [
"constructive algorithms",
"implementation",
"math"
] | A. Increasing Sequence | 1 | 64 | A sequence *a*0,<=*a*1,<=...,<=*a**t*<=-<=1 is called increasing if *a**i*<=-<=1<=<<=*a**i* for each *i*:<=0<=<<=*i*<=<<=*t*.
You are given a sequence *b*0,<=*b*1,<=...,<=*b**n*<=-<=1 and a positive integer *d*. In each move you may choose one element of the given sequence and add *d* to it. What is the least number of moves required to make the given sequence increasing? | The first line of the input contains two integer numbers *n* and *d* (2<=≤<=*n*<=≤<=2000,<=1<=≤<=*d*<=≤<=106). The second line contains space separated sequence *b*0,<=*b*1,<=...,<=*b**n*<=-<=1 (1<=≤<=*b**i*<=≤<=106). | Output the minimal number of moves needed to make the sequence increasing. | [
"4 2\n1 3 3 2\n"
] | [
"3\n"
] | none | [
{
"input": "4 2\n1 3 3 2",
"output": "3"
},
{
"input": "2 1\n1 1",
"output": "1"
},
{
"input": "2 1\n2 5",
"output": "0"
},
{
"input": "2 1\n1 2",
"output": "0"
},
{
"input": "2 1\n1 1",
"output": "1"
},
{
"input": "2 7\n10 20",
"output": "0"
},
... | 124 | 0 | 3.938 | 739 |
873 | Merge Sort | [
"constructive algorithms",
"divide and conquer"
] | null | null | Merge sort is a well-known sorting algorithm. The main function that sorts the elements of array *a* with indices from [*l*,<=*r*) can be implemented as follows:
1. If the segment [*l*,<=*r*) is already sorted in non-descending order (that is, for any *i* such that *l*<=≤<=*i*<=<<=*r*<=-<=1 *a*[*i*]<=≤<=*a*[*i*<=+<=1]), then end the function call; 1. Let ; 1. Call *mergesort*(*a*,<=*l*,<=*mid*); 1. Call *mergesort*(*a*,<=*mid*,<=*r*); 1. Merge segments [*l*,<=*mid*) and [*mid*,<=*r*), making the segment [*l*,<=*r*) sorted in non-descending order. The merge algorithm doesn't call any other functions.
The array in this problem is 0-indexed, so to sort the whole array, you need to call *mergesort*(*a*,<=0,<=*n*).
The number of calls of function *mergesort* is very important, so Ivan has decided to calculate it while sorting the array. For example, if *a*<==<={1,<=2,<=3,<=4}, then there will be 1 call of *mergesort* — *mergesort*(0,<=4), which will check that the array is sorted and then end. If *a*<==<={2,<=1,<=3}, then the number of calls is 3: first of all, you call *mergesort*(0,<=3), which then sets *mid*<==<=1 and calls *mergesort*(0,<=1) and *mergesort*(1,<=3), which do not perform any recursive calls because segments (0,<=1) and (1,<=3) are sorted.
Ivan has implemented the program that counts the number of *mergesort* calls, but now he needs to test it. To do this, he needs to find an array *a* such that *a* is a permutation of size *n* (that is, the number of elements in *a* is *n*, and every integer number from [1,<=*n*] can be found in this array), and the number of *mergesort* calls when sorting the array is exactly *k*.
Help Ivan to find an array he wants! | The first line contains two numbers *n* and *k* (1<=≤<=*n*<=≤<=100000, 1<=≤<=*k*<=≤<=200000) — the size of a desired permutation and the number of *mergesort* calls required to sort it. | If a permutation of size *n* such that there will be exactly *k* calls of *mergesort* while sorting it doesn't exist, output <=-<=1. Otherwise output *n* integer numbers *a*[0],<=*a*[1],<=...,<=*a*[*n*<=-<=1] — the elements of a permutation that would meet the required conditions. If there are multiple answers, print any of them. | [
"3 3\n",
"4 1\n",
"5 6\n"
] | [
"2 1 3 ",
"1 2 3 4 ",
"-1\n"
] | none | [
{
"input": "3 3",
"output": "2 1 3 "
},
{
"input": "4 1",
"output": "1 2 3 4 "
},
{
"input": "5 6",
"output": "-1"
},
{
"input": "100 100",
"output": "-1"
},
{
"input": "10000 10001",
"output": "3 1 5 2 7 4 8 10 6 12 9 13 15 11 17 14 18 20 16 22 19 23 25 21 27... | 77 | 7,168,000 | 3 | 740 | |
877 | Alex and broken contest | [
"implementation",
"strings"
] | null | null | One day Alex was creating a contest about his friends, but accidentally deleted it. Fortunately, all the problems were saved, but now he needs to find them among other problems.
But there are too many problems, to do it manually. Alex asks you to write a program, which will determine if a problem is from this contest by its name.
It is known, that problem is from this contest if and only if its name contains one of Alex's friends' name exactly once. His friends' names are "Danil", "Olya", "Slava", "Ann" and "Nikita".
Names are case sensitive. | The only line contains string from lowercase and uppercase letters and "_" symbols of length, not more than 100 — the name of the problem. | Print "YES", if problem is from this contest, and "NO" otherwise. | [
"Alex_and_broken_contest\n",
"NikitaAndString\n",
"Danil_and_Olya\n"
] | [
"NO",
"YES",
"NO"
] | none | [
{
"input": "Alex_and_broken_contest",
"output": "NO"
},
{
"input": "NikitaAndString",
"output": "YES"
},
{
"input": "Danil_and_Olya",
"output": "NO"
},
{
"input": "Slava____and_the_game",
"output": "YES"
},
{
"input": "Olya_and_energy_drinks",
"output": "YES"
... | 61 | 0 | 0 | 742 | |
624 | Making a String | [
"greedy",
"sortings"
] | null | null | You are given an alphabet consisting of *n* letters, your task is to make a string of the maximum possible length so that the following conditions are satisfied:
- the *i*-th letter occurs in the string no more than *a**i* times; - the number of occurrences of each letter in the string must be distinct for all the letters that occurred in the string at least once. | The first line of the input contains a single integer *n* (2<=<=≤<=<=*n*<=<=≤<=<=26) — the number of letters in the alphabet.
The next line contains *n* integers *a**i* (1<=≤<=*a**i*<=≤<=109) — *i*-th of these integers gives the limitation on the number of occurrences of the *i*-th character in the string. | Print a single integer — the maximum length of the string that meets all the requirements. | [
"3\n2 5 5\n",
"3\n1 1 2\n"
] | [
"11\n",
"3\n"
] | For convenience let's consider an alphabet consisting of three letters: "a", "b", "c". In the first sample, some of the optimal strings are: "cccaabbccbb", "aabcbcbcbcb". In the second sample some of the optimal strings are: "acc", "cbc". | [
{
"input": "3\n2 5 5",
"output": "11"
},
{
"input": "3\n1 1 2",
"output": "3"
},
{
"input": "2\n1 1",
"output": "1"
},
{
"input": "3\n1 1000000000 2",
"output": "1000000003"
},
{
"input": "26\n1000000000 1000000000 1000000000 1000000000 1000000000 1000000000 10000... | 124 | 0 | 3 | 743 | |
602 | Approximating a Constant Range | [
"dp",
"implementation",
"two pointers"
] | null | null | When Xellos was doing a practice course in university, he once had to measure the intensity of an effect that slowly approached equilibrium. A good way to determine the equilibrium intensity would be choosing a sufficiently large number of consecutive data points that seems as constant as possible and taking their average. Of course, with the usual sizes of data, it's nothing challenging — but why not make a similar programming contest problem while we're at it?
You're given a sequence of *n* data points *a*1,<=...,<=*a**n*. There aren't any big jumps between consecutive data points — for each 1<=≤<=*i*<=<<=*n*, it's guaranteed that |*a**i*<=+<=1<=-<=*a**i*|<=≤<=1.
A range [*l*,<=*r*] of data points is said to be almost constant if the difference between the largest and the smallest value in that range is at most 1. Formally, let *M* be the maximum and *m* the minimum value of *a**i* for *l*<=≤<=*i*<=≤<=*r*; the range [*l*,<=*r*] is almost constant if *M*<=-<=*m*<=≤<=1.
Find the length of the longest almost constant range. | The first line of the input contains a single integer *n* (2<=≤<=*n*<=≤<=100<=000) — the number of data points.
The second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=100<=000). | Print a single number — the maximum length of an almost constant range of the given sequence. | [
"5\n1 2 3 3 2\n",
"11\n5 4 5 5 6 7 8 8 8 7 6\n"
] | [
"4\n",
"5\n"
] | In the first sample, the longest almost constant range is [2, 5]; its length (the number of data points in it) is 4.
In the second sample, there are three almost constant ranges of length 4: [1, 4], [6, 9] and [7, 10]; the only almost constant range of the maximum length 5 is [6, 10]. | [
{
"input": "5\n1 2 3 3 2",
"output": "4"
},
{
"input": "11\n5 4 5 5 6 7 8 8 8 7 6",
"output": "5"
},
{
"input": "2\n3 2",
"output": "2"
},
{
"input": "4\n1001 1000 1000 1001",
"output": "4"
},
{
"input": "4\n1 1 2 3",
"output": "3"
},
{
"input": "3\n1 ... | 202 | 10,035,200 | 0 | 744 | |
320 | Magic Numbers | [
"brute force",
"greedy"
] | null | null | A magic number is a number formed by concatenation of numbers 1, 14 and 144. We can use each of these numbers any number of times. Therefore 14144, 141414 and 1411 are magic numbers but 1444, 514 and 414 are not.
You're given a number. Determine if it is a magic number or not. | The first line of input contains an integer *n*, (1<=≤<=*n*<=≤<=109). This number doesn't contain leading zeros. | Print "YES" if *n* is a magic number or print "NO" if it's not. | [
"114114\n",
"1111\n",
"441231\n"
] | [
"YES\n",
"YES\n",
"NO\n"
] | none | [
{
"input": "114114",
"output": "YES"
},
{
"input": "1111",
"output": "YES"
},
{
"input": "441231",
"output": "NO"
},
{
"input": "1",
"output": "YES"
},
{
"input": "14",
"output": "YES"
},
{
"input": "114",
"output": "YES"
},
{
"input": "9",... | 92 | 0 | 0 | 746 | |
1,006 | Polycarp's Practice | [
"greedy",
"implementation",
"sortings"
] | null | null | Polycarp is practicing his problem solving skill. He has a list of $n$ problems with difficulties $a_1, a_2, \dots, a_n$, respectively. His plan is to practice for exactly $k$ days. Each day he has to solve at least one problem from his list. Polycarp solves the problems in the order they are given in his list, he cannot skip any problem from his list. He has to solve all $n$ problems in exactly $k$ days.
Thus, each day Polycarp solves a contiguous sequence of (consecutive) problems from the start of the list. He can't skip problems or solve them multiple times. As a result, in $k$ days he will solve all the $n$ problems.
The profit of the $j$-th day of Polycarp's practice is the maximum among all the difficulties of problems Polycarp solves during the $j$-th day (i.e. if he solves problems with indices from $l$ to $r$ during a day, then the profit of the day is $\max\limits_{l \le i \le r}a_i$). The total profit of his practice is the sum of the profits over all $k$ days of his practice.
You want to help Polycarp to get the maximum possible total profit over all valid ways to solve problems. Your task is to distribute all $n$ problems between $k$ days satisfying the conditions above in such a way, that the total profit is maximum.
For example, if $n = 8, k = 3$ and $a = [5, 4, 2, 6, 5, 1, 9, 2]$, one of the possible distributions with maximum total profit is: $[5, 4, 2], [6, 5], [1, 9, 2]$. Here the total profit equals $5 + 6 + 9 = 20$. | The first line of the input contains two integers $n$ and $k$ ($1 \le k \le n \le 2000$) — the number of problems and the number of days, respectively.
The second line of the input contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 2000$) — difficulties of problems in Polycarp's list, in the order they are placed in the list (i.e. in the order Polycarp will solve them). | In the first line of the output print the maximum possible total profit.
In the second line print exactly $k$ positive integers $t_1, t_2, \dots, t_k$ ($t_1 + t_2 + \dots + t_k$ must equal $n$), where $t_j$ means the number of problems Polycarp will solve during the $j$-th day in order to achieve the maximum possible total profit of his practice.
If there are many possible answers, you may print any of them. | [
"8 3\n5 4 2 6 5 1 9 2\n",
"5 1\n1 1 1 1 1\n",
"4 2\n1 2000 2000 2\n"
] | [
"20\n3 2 3",
"1\n5\n",
"4000\n2 2\n"
] | The first example is described in the problem statement.
In the second example there is only one possible distribution.
In the third example the best answer is to distribute problems in the following way: $[1, 2000], [2000, 2]$. The total profit of this distribution is $2000 + 2000 = 4000$. | [
{
"input": "8 3\n5 4 2 6 5 1 9 2",
"output": "20\n4 1 3"
},
{
"input": "5 1\n1 1 1 1 1",
"output": "1\n5"
},
{
"input": "4 2\n1 2000 2000 2",
"output": "4000\n2 2"
},
{
"input": "1 1\n2000",
"output": "2000\n1"
},
{
"input": "1 1\n1234",
"output": "1234\n1"
... | 93 | 307,200 | 0 | 750 | |
347 | Difference Row | [
"constructive algorithms",
"implementation",
"sortings"
] | null | null | You want to arrange *n* integers *a*1,<=*a*2,<=...,<=*a**n* in some order in a row. Let's define the value of an arrangement as the sum of differences between all pairs of adjacent integers.
More formally, let's denote some arrangement as a sequence of integers *x*1,<=*x*2,<=...,<=*x**n*, where sequence *x* is a permutation of sequence *a*. The value of such an arrangement is (*x*1<=-<=*x*2)<=+<=(*x*2<=-<=*x*3)<=+<=...<=+<=(*x**n*<=-<=1<=-<=*x**n*).
Find the largest possible value of an arrangement. Then, output the lexicographically smallest sequence *x* that corresponds to an arrangement of the largest possible value. | The first line of the input contains integer *n* (2<=≤<=*n*<=≤<=100). The second line contains *n* space-separated integers *a*1, *a*2, ..., *a**n* (|*a**i*|<=≤<=1000). | Print the required sequence *x*1,<=*x*2,<=...,<=*x**n*. Sequence *x* should be the lexicographically smallest permutation of *a* that corresponds to an arrangement of the largest possible value. | [
"5\n100 -100 50 0 -50\n"
] | [
"100 -50 0 50 -100 \n"
] | In the sample test case, the value of the output arrangement is (100 - ( - 50)) + (( - 50) - 0) + (0 - 50) + (50 - ( - 100)) = 200. No other arrangement has a larger value, and among all arrangements with the value of 200, the output arrangement is the lexicographically smallest one.
Sequence *x*<sub class="lower-index">1</sub>, *x*<sub class="lower-index">2</sub>, ... , *x*<sub class="lower-index">*p*</sub> is lexicographically smaller than sequence *y*<sub class="lower-index">1</sub>, *y*<sub class="lower-index">2</sub>, ... , *y*<sub class="lower-index">*p*</sub> if there exists an integer *r* (0 ≤ *r* < *p*) such that *x*<sub class="lower-index">1</sub> = *y*<sub class="lower-index">1</sub>, *x*<sub class="lower-index">2</sub> = *y*<sub class="lower-index">2</sub>, ... , *x*<sub class="lower-index">*r*</sub> = *y*<sub class="lower-index">*r*</sub> and *x*<sub class="lower-index">*r* + 1</sub> < *y*<sub class="lower-index">*r* + 1</sub>. | [
{
"input": "5\n100 -100 50 0 -50",
"output": "100 -50 0 50 -100 "
},
{
"input": "10\n764 -367 0 963 -939 -795 -26 -49 948 -282",
"output": "963 -795 -367 -282 -49 -26 0 764 948 -939 "
},
{
"input": "20\n262 -689 -593 161 -678 -555 -633 -697 369 258 673 50 833 737 -650 198 -651 -621 -396 ... | 156 | 6,860,800 | 0 | 752 | |
299 | Ksusha and Array | [
"brute force",
"number theory",
"sortings"
] | null | null | Ksusha is a beginner coder. Today she starts studying arrays. She has array *a*1,<=*a*2,<=...,<=*a**n*, consisting of *n* positive integers.
Her university teacher gave her a task. Find such number in the array, that all array elements are divisible by it. Help her and find the number! | The first line contains integer *n* (1<=≤<=*n*<=≤<=105), showing how many numbers the array has. The next line contains integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=109) — the array elements. | Print a single integer — the number from the array, such that all array elements are divisible by it. If such number doesn't exist, print -1.
If there are multiple answers, you are allowed to print any of them. | [
"3\n2 2 4\n",
"5\n2 1 3 1 6\n",
"3\n2 3 5\n"
] | [
"2\n",
"1\n",
"-1\n"
] | none | [
{
"input": "3\n2 2 4",
"output": "2"
},
{
"input": "5\n2 1 3 1 6",
"output": "1"
},
{
"input": "3\n2 3 5",
"output": "-1"
},
{
"input": "1\n331358794",
"output": "331358794"
},
{
"input": "5\n506904227 214303304 136194869 838256937 183952885",
"output": "-1"
... | 156 | 0 | -1 | 753 | |
709 | Juicer | [
"implementation"
] | null | null | Kolya is going to make fresh orange juice. He has *n* oranges of sizes *a*1,<=*a*2,<=...,<=*a**n*. Kolya will put them in the juicer in the fixed order, starting with orange of size *a*1, then orange of size *a*2 and so on. To be put in the juicer the orange must have size not exceeding *b*, so if Kolya sees an orange that is strictly greater he throws it away and continues with the next one.
The juicer has a special section to collect waste. It overflows if Kolya squeezes oranges of the total size strictly greater than *d*. When it happens Kolya empties the waste section (even if there are no more oranges) and continues to squeeze the juice. How many times will he have to empty the waste section? | The first line of the input contains three integers *n*, *b* and *d* (1<=≤<=*n*<=≤<=100<=000, 1<=≤<=*b*<=≤<=*d*<=≤<=1<=000<=000) — the number of oranges, the maximum size of the orange that fits in the juicer and the value *d*, which determines the condition when the waste section should be emptied.
The second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=1<=000<=000) — sizes of the oranges listed in the order Kolya is going to try to put them in the juicer. | Print one integer — the number of times Kolya will have to empty the waste section. | [
"2 7 10\n5 6\n",
"1 5 10\n7\n",
"3 10 10\n5 7 7\n",
"1 1 1\n1\n"
] | [
"1\n",
"0\n",
"1\n",
"0\n"
] | In the first sample, Kolya will squeeze the juice from two oranges and empty the waste section afterwards.
In the second sample, the orange won't fit in the juicer so Kolya will have no juice at all. | [
{
"input": "2 7 10\n5 6",
"output": "1"
},
{
"input": "1 5 10\n7",
"output": "0"
},
{
"input": "3 10 10\n5 7 7",
"output": "1"
},
{
"input": "1 1 1\n1",
"output": "0"
},
{
"input": "2 951637 951638\n44069 951637",
"output": "1"
},
{
"input": "50 100 12... | 77 | 7,065,600 | 0 | 755 | |
258 | Little Elephant and Bits | [
"greedy",
"math"
] | null | null | The Little Elephant has an integer *a*, written in the binary notation. He wants to write this number on a piece of paper.
To make sure that the number *a* fits on the piece of paper, the Little Elephant ought to delete exactly one any digit from number *a* in the binary record. At that a new number appears. It consists of the remaining binary digits, written in the corresponding order (possible, with leading zeroes).
The Little Elephant wants the number he is going to write on the paper to be as large as possible. Help him find the maximum number that he can obtain after deleting exactly one binary digit and print it in the binary notation. | The single line contains integer *a*, written in the binary notation without leading zeroes. This number contains more than 1 and at most 105 digits. | In the single line print the number that is written without leading zeroes in the binary notation — the answer to the problem. | [
"101\n",
"110010\n"
] | [
"11\n",
"11010\n"
] | In the first sample the best strategy is to delete the second digit. That results in number 11<sub class="lower-index">2</sub> = 3<sub class="lower-index">10</sub>.
In the second sample the best strategy is to delete the third or fourth digits — that results in number 11010<sub class="lower-index">2</sub> = 26<sub class="lower-index">10</sub>. | [
{
"input": "101",
"output": "11"
},
{
"input": "110010",
"output": "11010"
},
{
"input": "10000",
"output": "1000"
},
{
"input": "1111111110",
"output": "111111111"
},
{
"input": "10100101011110101",
"output": "1100101011110101"
},
{
"input": "11101001... | 1,434 | 9,113,600 | 3 | 758 | |
725 | Jumping Ball | [
"implementation"
] | null | null | In a new version of the famous Pinball game, one of the most important parts of the game field is a sequence of *n* bumpers. The bumpers are numbered with integers from 1 to *n* from left to right. There are two types of bumpers. They are denoted by the characters '<' and '>'. When the ball hits the bumper at position *i* it goes one position to the right (to the position *i*<=+<=1) if the type of this bumper is '>', or one position to the left (to *i*<=-<=1) if the type of the bumper at position *i* is '<'. If there is no such position, in other words if *i*<=-<=1<=<<=1 or *i*<=+<=1<=><=*n*, the ball falls from the game field.
Depending on the ball's starting position, the ball may eventually fall from the game field or it may stay there forever. You are given a string representing the bumpers' types. Calculate the number of positions such that the ball will eventually fall from the game field if it starts at that position. | The first line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=200<=000) — the length of the sequence of bumpers. The second line contains the string, which consists of the characters '<' and '>'. The character at the *i*-th position of this string corresponds to the type of the *i*-th bumper. | Print one integer — the number of positions in the sequence such that the ball will eventually fall from the game field if it starts at that position. | [
"4\n<<><\n",
"5\n>>>>>\n",
"4\n>><<\n"
] | [
"2",
"5",
"0"
] | In the first sample, the ball will fall from the field if starts at position 1 or position 2.
In the second sample, any starting position will result in the ball falling from the field. | [
{
"input": "4\n<<><",
"output": "2"
},
{
"input": "5\n>>>>>",
"output": "5"
},
{
"input": "4\n>><<",
"output": "0"
},
{
"input": "3\n<<>",
"output": "3"
},
{
"input": "3\n<<<",
"output": "3"
},
{
"input": "3\n><<",
"output": "0"
},
{
"input... | 108 | 7,168,000 | -1 | 759 | |
358 | Dima and Continuous Line | [
"brute force",
"implementation"
] | null | null | Dima and Seryozha live in an ordinary dormitory room for two. One day Dima had a date with his girl and he asked Seryozha to leave the room. As a compensation, Seryozha made Dima do his homework.
The teacher gave Seryozha the coordinates of *n* distinct points on the abscissa axis and asked to consecutively connect them by semi-circus in a certain order: first connect the first point with the second one, then connect the second point with the third one, then the third one with the fourth one and so on to the *n*-th point. Two points with coordinates (*x*1,<=0) and (*x*2,<=0) should be connected by a semi-circle that passes above the abscissa axis with the diameter that coincides with the segment between points. Seryozha needs to find out if the line on the picture intersects itself. For clarifications, see the picture Seryozha showed to Dima (the left picture has self-intersections, the right picture doesn't have any).
Seryozha is not a small boy, so the coordinates of the points can be rather large. Help Dima cope with the problem. | The first line contains a single integer *n* (1<=≤<=*n*<=≤<=103). The second line contains *n* distinct integers *x*1,<=*x*2,<=...,<=*x**n* (<=-<=106<=≤<=*x**i*<=≤<=106) — the *i*-th point has coordinates (*x**i*,<=0). The points are not necessarily sorted by their *x* coordinate. | In the single line print "yes" (without the quotes), if the line has self-intersections. Otherwise, print "no" (without the quotes). | [
"4\n0 10 5 15\n",
"4\n0 15 5 10\n"
] | [
"yes\n",
"no\n"
] | The first test from the statement is on the picture to the left, the second test is on the picture to the right. | [
{
"input": "4\n0 10 5 15",
"output": "yes"
},
{
"input": "4\n0 15 5 10",
"output": "no"
},
{
"input": "5\n0 1000 2000 3000 1500",
"output": "yes"
},
{
"input": "5\n-724093 710736 -383722 -359011 439613",
"output": "no"
},
{
"input": "50\n384672 661179 -775591 -989... | 155 | 2,867,200 | 3 | 765 | |
742 | Arpa’s obvious problem and Mehrdad’s terrible solution | [
"brute force",
"math",
"number theory"
] | null | null | There are some beautiful girls in Arpa’s land as mentioned before.
Once Arpa came up with an obvious problem:
Given an array and a number *x*, count the number of pairs of indices *i*,<=*j* (1<=≤<=*i*<=<<=*j*<=≤<=*n*) such that , where is bitwise xor operation (see notes for explanation).
Immediately, Mehrdad discovered a terrible solution that nobody trusted. Now Arpa needs your help to implement the solution to that problem. | First line contains two integers *n* and *x* (1<=≤<=*n*<=≤<=105,<=0<=≤<=*x*<=≤<=105) — the number of elements in the array and the integer *x*.
Second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=105) — the elements of the array. | Print a single integer: the answer to the problem. | [
"2 3\n1 2\n",
"6 1\n5 1 2 3 4 1\n"
] | [
"1",
"2"
] | In the first sample there is only one pair of *i* = 1 and *j* = 2. <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/bec9071ce5b1039982fe0ae476cd31528ddfa2f3.png" style="max-width: 100.0%;max-height: 100.0%;"/> so the answer is 1.
In the second sample the only two pairs are *i* = 3, *j* = 4 (since <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/3701990d023d19c5da0b315b5057d572ec11e4fd.png" style="max-width: 100.0%;max-height: 100.0%;"/>) and *i* = 1, *j* = 5 (since <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/8c96223ca88621240a5ee6e1498acb7e4ce0eb44.png" style="max-width: 100.0%;max-height: 100.0%;"/>).
A bitwise xor takes two bit integers of equal length and performs the logical xor operation on each pair of corresponding bits. The result in each position is 1 if only the first bit is 1 or only the second bit is 1, but will be 0 if both are 0 or both are 1. You can read more about bitwise xor operation here: [https://en.wikipedia.org/wiki/Bitwise_operation#XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR). | [
{
"input": "2 3\n1 2",
"output": "1"
},
{
"input": "6 1\n5 1 2 3 4 1",
"output": "2"
},
{
"input": "38 101\n395 5 339 366 409 150 400 180 348 200 409 20 182 409 208 74 176 401 459 158 282 207 241 406 33 484 65 245 363 337 204 197 445 445 72 435 126 423",
"output": "0"
},
{
"i... | 77 | 4,505,600 | 0 | 766 | |
0 | none | [
"none"
] | null | null | Let's define the sum of two permutations *p* and *q* of numbers 0,<=1,<=...,<=(*n*<=-<=1) as permutation , where *Perm*(*x*) is the *x*-th lexicographically permutation of numbers 0,<=1,<=...,<=(*n*<=-<=1) (counting from zero), and *Ord*(*p*) is the number of permutation *p* in the lexicographical order.
For example, *Perm*(0)<==<=(0,<=1,<=...,<=*n*<=-<=2,<=*n*<=-<=1), *Perm*(*n*!<=-<=1)<==<=(*n*<=-<=1,<=*n*<=-<=2,<=...,<=1,<=0)
Misha has two permutations, *p* and *q*. Your task is to find their sum.
Permutation *a*<==<=(*a*0,<=*a*1,<=...,<=*a**n*<=-<=1) is called to be lexicographically smaller than permutation *b*<==<=(*b*0,<=*b*1,<=...,<=*b**n*<=-<=1), if for some *k* following conditions hold: *a*0<==<=*b*0,<=*a*1<==<=*b*1,<=...,<=*a**k*<=-<=1<==<=*b**k*<=-<=1,<=*a**k*<=<<=*b**k*. | The first line contains an integer *n* (1<=≤<=*n*<=≤<=200<=000).
The second line contains *n* distinct integers from 0 to *n*<=-<=1, separated by a space, forming permutation *p*.
The third line contains *n* distinct integers from 0 to *n*<=-<=1, separated by spaces, forming permutation *q*. | Print *n* distinct integers from 0 to *n*<=-<=1, forming the sum of the given permutations. Separate the numbers by spaces. | [
"2\n0 1\n0 1\n",
"2\n0 1\n1 0\n",
"3\n1 2 0\n2 1 0\n"
] | [
"0 1\n",
"1 0\n",
"1 0 2\n"
] | Permutations of numbers from 0 to 1 in the lexicographical order: (0, 1), (1, 0).
In the first sample *Ord*(*p*) = 0 and *Ord*(*q*) = 0, so the answer is <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/8ce4cd76db7c3f712f9101b410c36891976581b8.png" style="max-width: 100.0%;max-height: 100.0%;"/>.
In the second sample *Ord*(*p*) = 0 and *Ord*(*q*) = 1, so the answer is <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/5684e4e2deb5ed60419a5c9e765f0cd4cb995652.png" style="max-width: 100.0%;max-height: 100.0%;"/>.
Permutations of numbers from 0 to 2 in the lexicographical order: (0, 1, 2), (0, 2, 1), (1, 0, 2), (1, 2, 0), (2, 0, 1), (2, 1, 0).
In the third sample *Ord*(*p*) = 3 and *Ord*(*q*) = 5, so the answer is <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/da14f774ebda9f417649f5334d329ec7b7c07778.png" style="max-width: 100.0%;max-height: 100.0%;"/>. | [] | 2,000 | 85,811,200 | 0 | 768 | |
546 | Soldier and Bananas | [
"brute force",
"implementation",
"math"
] | null | null | A soldier wants to buy *w* bananas in the shop. He has to pay *k* dollars for the first banana, 2*k* dollars for the second one and so on (in other words, he has to pay *i*·*k* dollars for the *i*-th banana).
He has *n* dollars. How many dollars does he have to borrow from his friend soldier to buy *w* bananas? | The first line contains three positive integers *k*,<=*n*,<=*w* (1<=<=≤<=<=*k*,<=*w*<=<=≤<=<=1000, 0<=≤<=*n*<=≤<=109), the cost of the first banana, initial number of dollars the soldier has and number of bananas he wants. | Output one integer — the amount of dollars that the soldier must borrow from his friend. If he doesn't have to borrow money, output 0. | [
"3 17 4\n"
] | [
"13"
] | none | [
{
"input": "3 17 4",
"output": "13"
},
{
"input": "1 2 1",
"output": "0"
},
{
"input": "1 1 1",
"output": "0"
},
{
"input": "1 5 6",
"output": "16"
},
{
"input": "1 1000000000 1",
"output": "0"
},
{
"input": "1000 0 1000",
"output": "500500000"
}... | 31 | 0 | 3 | 769 | |
493 | Vasya and Chess | [
"constructive algorithms",
"games",
"math"
] | null | null | Vasya decided to learn to play chess. Classic chess doesn't seem interesting to him, so he plays his own sort of chess.
The queen is the piece that captures all squares on its vertical, horizontal and diagonal lines. If the cell is located on the same vertical, horizontal or diagonal line with queen, and the cell contains a piece of the enemy color, the queen is able to move to this square. After that the enemy's piece is removed from the board. The queen cannot move to a cell containing an enemy piece if there is some other piece between it and the queen.
There is an *n*<=×<=*n* chessboard. We'll denote a cell on the intersection of the *r*-th row and *c*-th column as (*r*,<=*c*). The square (1,<=1) contains the white queen and the square (1,<=*n*) contains the black queen. All other squares contain green pawns that don't belong to anyone.
The players move in turns. The player that moves first plays for the white queen, his opponent plays for the black queen.
On each move the player has to capture some piece with his queen (that is, move to a square that contains either a green pawn or the enemy queen). The player loses if either he cannot capture any piece during his move or the opponent took his queen during the previous move.
Help Vasya determine who wins if both players play with an optimal strategy on the board *n*<=×<=*n*. | The input contains a single number *n* (2<=≤<=*n*<=≤<=109) — the size of the board. | On the first line print the answer to problem — string "white" or string "black", depending on who wins if the both players play optimally.
If the answer is "white", then you should also print two integers *r* and *c* representing the cell (*r*,<=*c*), where the first player should make his first move to win. If there are multiple such cells, print the one with the minimum *r*. If there are still multiple squares, print the one with the minimum *c*. | [
"2\n",
"3\n"
] | [
"white\n1 2\n",
"black\n"
] | In the first sample test the white queen can capture the black queen at the first move, so the white player wins.
In the second test from the statement if the white queen captures the green pawn located on the central vertical line, then it will be captured by the black queen during the next move. So the only move for the white player is to capture the green pawn located at (2, 1).
Similarly, the black queen doesn't have any other options but to capture the green pawn located at (2, 3), otherwise if it goes to the middle vertical line, it will be captured by the white queen.
During the next move the same thing happens — neither the white, nor the black queen has other options rather than to capture green pawns situated above them. Thus, the white queen ends up on square (3, 1), and the black queen ends up on square (3, 3).
In this situation the white queen has to capture any of the green pawns located on the middle vertical line, after that it will be captured by the black queen. Thus, the player who plays for the black queen wins. | [
{
"input": "2",
"output": "white\n1 2"
},
{
"input": "3",
"output": "black"
},
{
"input": "4",
"output": "white\n1 2"
},
{
"input": "6",
"output": "white\n1 2"
},
{
"input": "10",
"output": "white\n1 2"
},
{
"input": "16",
"output": "white\n1 2"
... | 140 | 0 | 3 | 771 | |
729 | Sea Battle | [
"constructive algorithms",
"greedy",
"math"
] | null | null | Galya is playing one-dimensional Sea Battle on a 1<=×<=*n* grid. In this game *a* ships are placed on the grid. Each of the ships consists of *b* consecutive cells. No cell can be part of two ships, however, the ships can touch each other.
Galya doesn't know the ships location. She can shoot to some cells and after each shot she is told if that cell was a part of some ship (this case is called "hit") or not (this case is called "miss").
Galya has already made *k* shots, all of them were misses.
Your task is to calculate the minimum number of cells such that if Galya shoot at all of them, she would hit at least one ship.
It is guaranteed that there is at least one valid ships placement. | The first line contains four positive integers *n*, *a*, *b*, *k* (1<=≤<=*n*<=≤<=2·105, 1<=≤<=*a*,<=*b*<=≤<=*n*, 0<=≤<=*k*<=≤<=*n*<=-<=1) — the length of the grid, the number of ships on the grid, the length of each ship and the number of shots Galya has already made.
The second line contains a string of length *n*, consisting of zeros and ones. If the *i*-th character is one, Galya has already made a shot to this cell. Otherwise, she hasn't. It is guaranteed that there are exactly *k* ones in this string. | In the first line print the minimum number of cells such that if Galya shoot at all of them, she would hit at least one ship.
In the second line print the cells Galya should shoot at.
Each cell should be printed exactly once. You can print the cells in arbitrary order. The cells are numbered from 1 to *n*, starting from the left.
If there are multiple answers, you can print any of them. | [
"5 1 2 1\n00100\n",
"13 3 2 3\n1000000010001\n"
] | [
"2\n4 2\n",
"2\n7 11\n"
] | There is one ship in the first sample. It can be either to the left or to the right from the shot Galya has already made (the "1" character). So, it is necessary to make two shots: one at the left part, and one at the right part. | [
{
"input": "5 1 2 1\n00100",
"output": "2\n2 5 "
},
{
"input": "13 3 2 3\n1000000010001",
"output": "2\n3 5 "
},
{
"input": "1 1 1 0\n0",
"output": "1\n1 "
},
{
"input": "2 2 1 0\n00",
"output": "1\n1 "
},
{
"input": "5 4 1 0\n00000",
"output": "2\n1 2 "
},
... | 296 | 18,841,600 | 3 | 772 | |
92 | Chips | [
"implementation",
"math"
] | A. Chips | 2 | 256 | There are *n* walruses sitting in a circle. All of them are numbered in the clockwise order: the walrus number 2 sits to the left of the walrus number 1, the walrus number 3 sits to the left of the walrus number 2, ..., the walrus number 1 sits to the left of the walrus number *n*.
The presenter has *m* chips. The presenter stands in the middle of the circle and starts giving the chips to the walruses starting from walrus number 1 and moving clockwise. The walrus number *i* gets *i* chips. If the presenter can't give the current walrus the required number of chips, then the presenter takes the remaining chips and the process ends. Determine by the given *n* and *m* how many chips the presenter will get in the end. | The first line contains two integers *n* and *m* (1<=≤<=*n*<=≤<=50, 1<=≤<=*m*<=≤<=104) — the number of walruses and the number of chips correspondingly. | Print the number of chips the presenter ended up with. | [
"4 11\n",
"17 107\n",
"3 8\n"
] | [
"0\n",
"2\n",
"1\n"
] | In the first sample the presenter gives one chip to the walrus number 1, two chips to the walrus number 2, three chips to the walrus number 3, four chips to the walrus number 4, then again one chip to the walrus number 1. After that the presenter runs out of chips. He can't give anything to the walrus number 2 and the process finishes.
In the third sample the presenter gives one chip to the walrus number 1, two chips to the walrus number 2, three chips to the walrus number 3, then again one chip to the walrus number 1. The presenter has one chip left and he can't give two chips to the walrus number 2, that's why the presenter takes the last chip. | [
{
"input": "4 11",
"output": "0"
},
{
"input": "17 107",
"output": "2"
},
{
"input": "3 8",
"output": "1"
},
{
"input": "46 7262",
"output": "35"
},
{
"input": "32 6864",
"output": "0"
},
{
"input": "36 6218",
"output": "14"
},
{
"input": "... | 62 | 0 | -1 | 778 |
677 | Vanya and Fence | [
"implementation"
] | null | null | Vanya and his friends are walking along the fence of height *h* and they do not want the guard to notice them. In order to achieve this the height of each of the friends should not exceed *h*. If the height of some person is greater than *h* he can bend down and then he surely won't be noticed by the guard. The height of the *i*-th person is equal to *a**i*.
Consider the width of the person walking as usual to be equal to 1, while the width of the bent person is equal to 2. Friends want to talk to each other while walking, so they would like to walk in a single row. What is the minimum width of the road, such that friends can walk in a row and remain unattended by the guard? | The first line of the input contains two integers *n* and *h* (1<=≤<=*n*<=≤<=1000, 1<=≤<=*h*<=≤<=1000) — the number of friends and the height of the fence, respectively.
The second line contains *n* integers *a**i* (1<=≤<=*a**i*<=≤<=2*h*), the *i*-th of them is equal to the height of the *i*-th person. | Print a single integer — the minimum possible valid width of the road. | [
"3 7\n4 5 14\n",
"6 1\n1 1 1 1 1 1\n",
"6 5\n7 6 8 9 10 5\n"
] | [
"4\n",
"6\n",
"11\n"
] | In the first sample, only person number 3 must bend down, so the required width is equal to 1 + 1 + 2 = 4.
In the second sample, all friends are short enough and no one has to bend, so the width 1 + 1 + 1 + 1 + 1 + 1 = 6 is enough.
In the third sample, all the persons have to bend, except the last one. The required minimum width of the road is equal to 2 + 2 + 2 + 2 + 2 + 1 = 11. | [
{
"input": "3 7\n4 5 14",
"output": "4"
},
{
"input": "6 1\n1 1 1 1 1 1",
"output": "6"
},
{
"input": "6 5\n7 6 8 9 10 5",
"output": "11"
},
{
"input": "10 420\n214 614 297 675 82 740 174 23 255 15",
"output": "13"
},
{
"input": "10 561\n657 23 1096 487 785 66 481... | 0 | 0 | -1 | 781 | |
819 | Mister B and Boring Game | [
"games",
"greedy"
] | null | null | Sometimes Mister B has free evenings when he doesn't know what to do. Fortunately, Mister B found a new game, where the player can play against aliens.
All characters in this game are lowercase English letters. There are two players: Mister B and his competitor.
Initially the players have a string *s* consisting of the first *a* English letters in alphabetical order (for example, if *a*<==<=5, then *s* equals to "abcde").
The players take turns appending letters to string *s*. Mister B moves first.
Mister B must append exactly *b* letters on each his move. He can arbitrary choose these letters. His opponent adds exactly *a* letters on each move.
Mister B quickly understood that his opponent was just a computer that used a simple algorithm. The computer on each turn considers the suffix of string *s* of length *a* and generates a string *t* of length *a* such that all letters in the string *t* are distinct and don't appear in the considered suffix. From multiple variants of *t* lexicographically minimal is chosen (if *a*<==<=4 and the suffix is "bfdd", the computer chooses string *t* equal to "aceg"). After that the chosen string *t* is appended to the end of *s*.
Mister B soon found the game boring and came up with the following question: what can be the minimum possible number of different letters in string *s* on the segment between positions *l* and *r*, inclusive. Letters of string *s* are numerated starting from 1. | First and only line contains four space-separated integers: *a*, *b*, *l* and *r* (1<=≤<=*a*,<=*b*<=≤<=12, 1<=≤<=*l*<=≤<=*r*<=≤<=109) — the numbers of letters each player appends and the bounds of the segment. | Print one integer — the minimum possible number of different letters in the segment from position *l* to position *r*, inclusive, in string *s*. | [
"1 1 1 8\n",
"4 2 2 6\n",
"3 7 4 6\n"
] | [
"2",
"3",
"1"
] | In the first sample test one of optimal strategies generate string *s* = "abababab...", that's why answer is 2.
In the second sample test string *s* = "abcdbcaefg..." can be obtained, chosen segment will look like "bcdbc", that's why answer is 3.
In the third sample test string *s* = "abczzzacad..." can be obtained, chosen, segment will look like "zzz", that's why answer is 1. | [
{
"input": "1 1 1 8",
"output": "2"
},
{
"input": "4 2 2 6",
"output": "3"
},
{
"input": "3 7 4 6",
"output": "1"
},
{
"input": "4 5 1 1",
"output": "1"
},
{
"input": "12 12 1 1000",
"output": "13"
},
{
"input": "12 1 1000 1000",
"output": "1"
},... | 46 | 0 | 0 | 783 | |
937 | Vile Grasshoppers | [
"brute force",
"math",
"number theory"
] | null | null | The weather is fine today and hence it's high time to climb the nearby pine and enjoy the landscape.
The pine's trunk includes several branches, located one above another and numbered from 2 to *y*. Some of them (more precise, from 2 to *p*) are occupied by tiny vile grasshoppers which you're at war with. These grasshoppers are known for their awesome jumping skills: the grasshopper at branch *x* can jump to branches .
Keeping this in mind, you wisely decided to choose such a branch that none of the grasshoppers could interrupt you. At the same time you wanna settle as high as possible since the view from up there is simply breathtaking.
In other words, your goal is to find the highest branch that cannot be reached by any of the grasshoppers or report that it's impossible. | The only line contains two integers *p* and *y* (2<=≤<=*p*<=≤<=*y*<=≤<=109). | Output the number of the highest suitable branch. If there are none, print -1 instead. | [
"3 6\n",
"3 4\n"
] | [
"5\n",
"-1\n"
] | In the first sample case grasshopper from branch 2 reaches branches 2, 4 and 6 while branch 3 is initially settled by another grasshopper. Therefore the answer is 5.
It immediately follows that there are no valid branches in second sample case. | [
{
"input": "3 6",
"output": "5"
},
{
"input": "3 4",
"output": "-1"
},
{
"input": "2 2",
"output": "-1"
},
{
"input": "5 50",
"output": "49"
},
{
"input": "944192806 944193066",
"output": "944192807"
},
{
"input": "1000000000 1000000000",
"output":... | 93 | 7,065,600 | 3 | 784 | |
3 | Shortest path of the king | [
"greedy",
"shortest paths"
] | A. Shortest path of the king | 1 | 64 | The king is left alone on the chessboard. In spite of this loneliness, he doesn't lose heart, because he has business of national importance. For example, he has to pay an official visit to square *t*. As the king is not in habit of wasting his time, he wants to get from his current position *s* to square *t* in the least number of moves. Help him to do this.
In one move the king can get to the square that has a common side or a common vertex with the square the king is currently in (generally there are 8 different squares he can move to). | The first line contains the chessboard coordinates of square *s*, the second line — of square *t*.
Chessboard coordinates consist of two characters, the first one is a lowercase Latin letter (from a to h), the second one is a digit from 1 to 8. | In the first line print *n* — minimum number of the king's moves. Then in *n* lines print the moves themselves. Each move is described with one of the 8: L, R, U, D, LU, LD, RU or RD.
L, R, U, D stand respectively for moves left, right, up and down (according to the picture), and 2-letter combinations stand for diagonal moves. If the answer is not unique, print any of them. | [
"a8\nh1\n"
] | [
"7\nRD\nRD\nRD\nRD\nRD\nRD\nRD\n"
] | none | [
{
"input": "a8\nh1",
"output": "7\nRD\nRD\nRD\nRD\nRD\nRD\nRD"
},
{
"input": "b2\nb4",
"output": "2\nU\nU"
},
{
"input": "a5\na5",
"output": "0"
},
{
"input": "h1\nb2",
"output": "6\nLU\nL\nL\nL\nL\nL"
},
{
"input": "c5\nh2",
"output": "5\nRD\nRD\nRD\nR\nR"
... | 186 | 2,764,800 | 0 | 785 |
7 | Kalevitch and Chess | [
"brute force",
"constructive algorithms"
] | A. Kalevitch and Chess | 2 | 64 | A famous Berland's painter Kalevitch likes to shock the public. One of his last obsessions is chess. For more than a thousand years people have been playing this old game on uninteresting, monotonous boards. Kalevitch decided to put an end to this tradition and to introduce a new attitude to chessboards.
As before, the chessboard is a square-checkered board with the squares arranged in a 8<=×<=8 grid, each square is painted black or white. Kalevitch suggests that chessboards should be painted in the following manner: there should be chosen a horizontal or a vertical line of 8 squares (i.e. a row or a column), and painted black. Initially the whole chessboard is white, and it can be painted in the above described way one or more times. It is allowed to paint a square many times, but after the first time it does not change its colour any more and remains black. Kalevitch paints chessboards neatly, and it is impossible to judge by an individual square if it was painted with a vertical or a horizontal stroke.
Kalevitch hopes that such chessboards will gain popularity, and he will be commissioned to paint chessboards, which will help him ensure a comfortable old age. The clients will inform him what chessboard they want to have, and the painter will paint a white chessboard meeting the client's requirements.
It goes without saying that in such business one should economize on everything — for each commission he wants to know the minimum amount of strokes that he has to paint to fulfill the client's needs. You are asked to help Kalevitch with this task. | The input file contains 8 lines, each of the lines contains 8 characters. The given matrix describes the client's requirements, W character stands for a white square, and B character — for a square painted black.
It is guaranteed that client's requirments can be fulfilled with a sequence of allowed strokes (vertical/column or horizontal/row). | Output the only number — the minimum amount of rows and columns that Kalevitch has to paint on the white chessboard to meet the client's requirements. | [
"WWWBWWBW\nBBBBBBBB\nWWWBWWBW\nWWWBWWBW\nWWWBWWBW\nWWWBWWBW\nWWWBWWBW\nWWWBWWBW\n",
"WWWWWWWW\nBBBBBBBB\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\n"
] | [
"3\n",
"1\n"
] | none | [
{
"input": "WWWBWWBW\nBBBBBBBB\nWWWBWWBW\nWWWBWWBW\nWWWBWWBW\nWWWBWWBW\nWWWBWWBW\nWWWBWWBW",
"output": "3"
},
{
"input": "WWWWWWWW\nBBBBBBBB\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW",
"output": "1"
},
{
"input": "WWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWWWW\nWWWWWW... | 124 | 0 | 3.969 | 788 |
659 | Round House | [
"implementation",
"math"
] | null | null | Vasya lives in a round building, whose entrances are numbered sequentially by integers from 1 to *n*. Entrance *n* and entrance 1 are adjacent.
Today Vasya got bored and decided to take a walk in the yard. Vasya lives in entrance *a* and he decided that during his walk he will move around the house *b* entrances in the direction of increasing numbers (in this order entrance *n* should be followed by entrance 1). The negative value of *b* corresponds to moving |*b*| entrances in the order of decreasing numbers (in this order entrance 1 is followed by entrance *n*). If *b*<==<=0, then Vasya prefers to walk beside his entrance.
Help Vasya to determine the number of the entrance, near which he will be at the end of his walk. | The single line of the input contains three space-separated integers *n*, *a* and *b* (1<=≤<=*n*<=≤<=100,<=1<=≤<=*a*<=≤<=*n*,<=<=-<=100<=≤<=*b*<=≤<=100) — the number of entrances at Vasya's place, the number of his entrance and the length of his walk, respectively. | Print a single integer *k* (1<=≤<=*k*<=≤<=*n*) — the number of the entrance where Vasya will be at the end of his walk. | [
"6 2 -5\n",
"5 1 3\n",
"3 2 7\n"
] | [
"3\n",
"4\n",
"3\n"
] | The first example is illustrated by the picture in the statements. | [
{
"input": "6 2 -5",
"output": "3"
},
{
"input": "5 1 3",
"output": "4"
},
{
"input": "3 2 7",
"output": "3"
},
{
"input": "1 1 0",
"output": "1"
},
{
"input": "1 1 -1",
"output": "1"
},
{
"input": "1 1 1",
"output": "1"
},
{
"input": "100 ... | 77 | 0 | 0 | 790 | |
747 | Display Size | [
"brute force",
"math"
] | null | null | A big company decided to launch a new series of rectangular displays, and decided that the display must have exactly *n* pixels.
Your task is to determine the size of the rectangular display — the number of lines (rows) of pixels *a* and the number of columns of pixels *b*, so that:
- there are exactly *n* pixels on the display; - the number of rows does not exceed the number of columns, it means *a*<=≤<=*b*; - the difference *b*<=-<=*a* is as small as possible. | The first line contains the positive integer *n* (1<=≤<=*n*<=≤<=106) — the number of pixels display should have. | Print two integers — the number of rows and columns on the display. | [
"8\n",
"64\n",
"5\n",
"999999\n"
] | [
"2 4\n",
"8 8\n",
"1 5\n",
"999 1001\n"
] | In the first example the minimum possible difference equals 2, so on the display should be 2 rows of 4 pixels.
In the second example the minimum possible difference equals 0, so on the display should be 8 rows of 8 pixels.
In the third example the minimum possible difference equals 4, so on the display should be 1 row of 5 pixels. | [
{
"input": "8",
"output": "2 4"
},
{
"input": "64",
"output": "8 8"
},
{
"input": "5",
"output": "1 5"
},
{
"input": "999999",
"output": "999 1001"
},
{
"input": "716539",
"output": "97 7387"
},
{
"input": "1",
"output": "1 1"
},
{
"input":... | 93 | 0 | 3 | 791 | |
0 | none | [
"none"
] | null | null | Little Nastya has a hobby, she likes to remove some letters from word, to obtain another word. But it turns out to be pretty hard for her, because she is too young. Therefore, her brother Sergey always helps her.
Sergey gives Nastya the word *t* and wants to get the word *p* out of it. Nastya removes letters in a certain order (one after another, in this order strictly), which is specified by permutation of letters' indices of the word *t*: *a*1... *a*|*t*|. We denote the length of word *x* as |*x*|. Note that after removing one letter, the indices of other letters don't change. For example, if *t*<==<="nastya" and *a*<==<=[4,<=1,<=5,<=3,<=2,<=6] then removals make the following sequence of words "nastya" "nastya" "nastya" "nastya" "nastya" "nastya" "nastya".
Sergey knows this permutation. His goal is to stop his sister at some point and continue removing by himself to get the word *p*. Since Nastya likes this activity, Sergey wants to stop her as late as possible. Your task is to determine, how many letters Nastya can remove before she will be stopped by Sergey.
It is guaranteed that the word *p* can be obtained by removing the letters from word *t*. | The first and second lines of the input contain the words *t* and *p*, respectively. Words are composed of lowercase letters of the Latin alphabet (1<=≤<=|*p*|<=<<=|*t*|<=≤<=200<=000). It is guaranteed that the word *p* can be obtained by removing the letters from word *t*.
Next line contains a permutation *a*1,<=*a*2,<=...,<=*a*|*t*| of letter indices that specifies the order in which Nastya removes letters of *t* (1<=≤<=*a**i*<=≤<=|*t*|, all *a**i* are distinct). | Print a single integer number, the maximum number of letters that Nastya can remove. | [
"ababcba\nabb\n5 3 4 1 7 6 2\n",
"bbbabb\nbb\n1 6 3 4 2 5\n"
] | [
"3",
"4"
] | In the first sample test sequence of removing made by Nastya looks like this:
"ababcba" <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png" style="max-width: 100.0%;max-height: 100.0%;"/> "ababcba" <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png" style="max-width: 100.0%;max-height: 100.0%;"/> "ababcba" <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png" style="max-width: 100.0%;max-height: 100.0%;"/> "ababcba"
Nastya can not continue, because it is impossible to get word "abb" from word "ababcba".
So, Nastya will remove only three letters. | [
{
"input": "ababcba\nabb\n5 3 4 1 7 6 2",
"output": "3"
},
{
"input": "bbbabb\nbb\n1 6 3 4 2 5",
"output": "4"
},
{
"input": "cacaccccccacccc\ncacc\n10 9 14 5 1 7 15 3 6 12 4 8 11 13 2",
"output": "9"
},
{
"input": "aaaabaaabaabaaaaaaaa\naaaa\n18 5 4 6 13 9 1 3 7 8 16 10 12 1... | 2,000 | 47,820,800 | 0 | 792 | |
260 | Adding Digits | [
"implementation",
"math"
] | null | null | Vasya has got two number: *a* and *b*. However, Vasya finds number *a* too short. So he decided to repeat the operation of lengthening number *a* *n* times.
One operation of lengthening a number means adding exactly one digit to the number (in the decimal notation) to the right provided that the resulting number is divisible by Vasya's number *b*. If it is impossible to obtain the number which is divisible by *b*, then the lengthening operation cannot be performed.
Your task is to help Vasya and print the number he can get after applying the lengthening operation to number *a* *n* times. | The first line contains three integers: *a*,<=*b*,<=*n* (1<=≤<=*a*,<=*b*,<=*n*<=≤<=105). | In a single line print the integer without leading zeros, which Vasya can get when he applies the lengthening operations to number *a* *n* times. If no such number exists, then print number -1. If there are multiple possible answers, print any of them. | [
"5 4 5\n",
"12 11 1\n",
"260 150 10\n"
] | [
"524848\n",
"121\n",
"-1\n"
] | none | [
{
"input": "5 4 5",
"output": "524848"
},
{
"input": "12 11 1",
"output": "121"
},
{
"input": "260 150 10",
"output": "-1"
},
{
"input": "78843 5684 42717",
"output": "-1"
},
{
"input": "93248 91435 1133",
"output": "-1"
},
{
"input": "100000 10 64479"... | 764 | 409,600 | 3 | 793 | |
37 | Towers | [
"sortings"
] | A. Towers | 2 | 256 | Little Vasya has received a young builder’s kit. The kit consists of several wooden bars, the lengths of all of them are known. The bars can be put one on the top of the other if their lengths are the same.
Vasya wants to construct the minimal number of towers from the bars. Help Vasya to use the bars in the best way possible. | The first line contains an integer *N* (1<=≤<=*N*<=≤<=1000) — the number of bars at Vasya’s disposal. The second line contains *N* space-separated integers *l**i* — the lengths of the bars. All the lengths are natural numbers not exceeding 1000. | In one line output two numbers — the height of the largest tower and their total number. Remember that Vasya should use all the bars. | [
"3\n1 2 3\n",
"4\n6 5 6 7\n"
] | [
"1 3\n",
"2 3\n"
] | none | [
{
"input": "3\n1 2 3",
"output": "1 3"
},
{
"input": "4\n6 5 6 7",
"output": "2 3"
},
{
"input": "4\n3 2 1 1",
"output": "2 3"
},
{
"input": "4\n1 2 3 3",
"output": "2 3"
},
{
"input": "3\n20 22 36",
"output": "1 3"
},
{
"input": "25\n47 30 94 41 45 20... | 218 | 6,963,200 | 3.93253 | 801 |
259 | Little Elephant and Chess | [
"brute force",
"strings"
] | null | null | The Little Elephant loves chess very much.
One day the Little Elephant and his friend decided to play chess. They've got the chess pieces but the board is a problem. They've got an 8<=×<=8 checkered board, each square is painted either black or white. The Little Elephant and his friend know that a proper chessboard doesn't have any side-adjacent cells with the same color and the upper left cell is white. To play chess, they want to make the board they have a proper chessboard. For that the friends can choose any row of the board and cyclically shift the cells of the chosen row, that is, put the last (rightmost) square on the first place in the row and shift the others one position to the right. You can run the described operation multiple times (or not run it at all).
For example, if the first line of the board looks like that "BBBBBBWW" (the white cells of the line are marked with character "W", the black cells are marked with character "B"), then after one cyclic shift it will look like that "WBBBBBBW".
Help the Little Elephant and his friend to find out whether they can use any number of the described operations to turn the board they have into a proper chessboard. | The input consists of exactly eight lines. Each line contains exactly eight characters "W" or "B" without any spaces: the *j*-th character in the *i*-th line stands for the color of the *j*-th cell of the *i*-th row of the elephants' board. Character "W" stands for the white color, character "B" stands for the black color.
Consider the rows of the board numbered from 1 to 8 from top to bottom, and the columns — from 1 to 8 from left to right. The given board can initially be a proper chessboard. | In a single line print "YES" (without the quotes), if we can make the board a proper chessboard and "NO" (without the quotes) otherwise. | [
"WBWBWBWB\nBWBWBWBW\nBWBWBWBW\nBWBWBWBW\nWBWBWBWB\nWBWBWBWB\nBWBWBWBW\nWBWBWBWB\n",
"WBWBWBWB\nWBWBWBWB\nBBWBWWWB\nBWBWBWBW\nBWBWBWBW\nBWBWBWWW\nBWBWBWBW\nBWBWBWBW\n"
] | [
"YES\n",
"NO\n"
] | In the first sample you should shift the following lines one position to the right: the 3-rd, the 6-th, the 7-th and the 8-th.
In the second sample there is no way you can achieve the goal. | [
{
"input": "WBWBWBWB\nBWBWBWBW\nBWBWBWBW\nBWBWBWBW\nWBWBWBWB\nWBWBWBWB\nBWBWBWBW\nWBWBWBWB",
"output": "YES"
},
{
"input": "WBWBWBWB\nWBWBWBWB\nBBWBWWWB\nBWBWBWBW\nBWBWBWBW\nBWBWBWWW\nBWBWBWBW\nBWBWBWBW",
"output": "NO"
},
{
"input": "BWBWBWBW\nWBWBWBWB\nBWBWBWBW\nBWBWBWBW\nWBWBWBWB\nWBW... | 280 | 0 | 0 | 802 | |
628 | Bear and String Distance | [
"greedy",
"strings"
] | null | null | Limak is a little polar bear. He likes nice strings — strings of length *n*, consisting of lowercase English letters only.
The distance between two letters is defined as the difference between their positions in the alphabet. For example, , and .
Also, the distance between two nice strings is defined as the sum of distances of corresponding letters. For example, , and .
Limak gives you a nice string *s* and an integer *k*. He challenges you to find any nice string *s*' that . Find any *s*' satisfying the given conditions, or print "-1" if it's impossible to do so.
As input/output can reach huge size it is recommended to use fast input/output methods: for example, prefer to use gets/scanf/printf instead of getline/cin/cout in C++, prefer to use BufferedReader/PrintWriter instead of Scanner/System.out in Java. | The first line contains two integers *n* and *k* (1<=≤<=*n*<=≤<=105, 0<=≤<=*k*<=≤<=106).
The second line contains a string *s* of length *n*, consisting of lowercase English letters. | If there is no string satisfying the given conditions then print "-1" (without the quotes).
Otherwise, print any nice string *s*' that . | [
"4 26\nbear\n",
"2 7\naf\n",
"3 1000\nhey\n"
] | [
"roar",
"db\n",
"-1\n"
] | none | [
{
"input": "4 26\nbear",
"output": "zcar"
},
{
"input": "2 7\naf",
"output": "hf"
},
{
"input": "3 1000\nhey",
"output": "-1"
},
{
"input": "5 50\nkzsij",
"output": "zaiij"
},
{
"input": "5 500\nvsdxg",
"output": "-1"
},
{
"input": "1 0\na",
"outpu... | 218 | 716,800 | 3 | 805 | |
451 | Sort the Array | [
"implementation",
"sortings"
] | null | null | Being a programmer, you like arrays a lot. For your birthday, your friends have given you an array *a* consisting of *n* distinct integers.
Unfortunately, the size of *a* is too small. You want a bigger array! Your friends agree to give you a bigger array, but only if you are able to answer the following question correctly: is it possible to sort the array *a* (in increasing order) by reversing exactly one segment of *a*? See definitions of segment and reversing in the notes. | The first line of the input contains an integer *n* (1<=≤<=*n*<=≤<=105) — the size of array *a*.
The second line contains *n* distinct space-separated integers: *a*[1],<=*a*[2],<=...,<=*a*[*n*] (1<=≤<=*a*[*i*]<=≤<=109). | Print "yes" or "no" (without quotes), depending on the answer.
If your answer is "yes", then also print two space-separated integers denoting start and end (start must not be greater than end) indices of the segment to be reversed. If there are multiple ways of selecting these indices, print any of them. | [
"3\n3 2 1\n",
"4\n2 1 3 4\n",
"4\n3 1 2 4\n",
"2\n1 2\n"
] | [
"yes\n1 3\n",
"yes\n1 2\n",
"no\n",
"yes\n1 1\n"
] | Sample 1. You can reverse the entire array to get [1, 2, 3], which is sorted.
Sample 3. No segment can be reversed such that the array will be sorted.
Definitions
A segment [*l*, *r*] of array *a* is the sequence *a*[*l*], *a*[*l* + 1], ..., *a*[*r*].
If you have an array *a* of size *n* and you reverse its segment [*l*, *r*], the array will become:
*a*[1], *a*[2], ..., *a*[*l* - 2], *a*[*l* - 1], *a*[*r*], *a*[*r* - 1], ..., *a*[*l* + 1], *a*[*l*], *a*[*r* + 1], *a*[*r* + 2], ..., *a*[*n* - 1], *a*[*n*]. | [
{
"input": "3\n3 2 1",
"output": "yes\n1 3"
},
{
"input": "4\n2 1 3 4",
"output": "yes\n1 2"
},
{
"input": "4\n3 1 2 4",
"output": "no"
},
{
"input": "2\n1 2",
"output": "yes\n1 1"
},
{
"input": "2\n58 4",
"output": "yes\n1 2"
},
{
"input": "5\n69 37 2... | 15 | 0 | 0 | 809 | |
299 | Ksusha the Squirrel | [
"brute force",
"implementation"
] | null | null | Ksusha the Squirrel is standing at the beginning of a straight road, divided into *n* sectors. The sectors are numbered 1 to *n*, from left to right. Initially, Ksusha stands in sector 1.
Ksusha wants to walk to the end of the road, that is, get to sector *n*. Unfortunately, there are some rocks on the road. We know that Ksusha hates rocks, so she doesn't want to stand in sectors that have rocks.
Ksusha the squirrel keeps fit. She can jump from sector *i* to any of the sectors *i*<=+<=1,<=*i*<=+<=2,<=...,<=*i*<=+<=*k*.
Help Ksusha! Given the road description, say if she can reach the end of the road (note, she cannot stand on a rock)? | The first line contains two integers *n* and *k* (2<=≤<=*n*<=≤<=3·105,<=1<=≤<=*k*<=≤<=3·105). The next line contains *n* characters — the description of the road: the *i*-th character equals ".", if the *i*-th sector contains no rocks. Otherwise, it equals "#".
It is guaranteed that the first and the last characters equal ".". | Print "YES" (without the quotes) if Ksusha can reach the end of the road, otherwise print "NO" (without the quotes). | [
"2 1\n..\n",
"5 2\n.#.#.\n",
"7 3\n.#.###.\n"
] | [
"YES\n",
"YES\n",
"NO\n"
] | none | [
{
"input": "2 1\n..",
"output": "YES"
},
{
"input": "5 2\n.#.#.",
"output": "YES"
},
{
"input": "7 3\n.#.###.",
"output": "NO"
},
{
"input": "2 200\n..",
"output": "YES"
},
{
"input": "2 1\n..",
"output": "YES"
},
{
"input": "2 2\n..",
"output": "Y... | 280 | 4,710,400 | 3 | 810 | |
556 | Case of the Zeros and Ones | [
"greedy"
] | null | null | Andrewid the Android is a galaxy-famous detective. In his free time he likes to think about strings containing zeros and ones.
Once he thought about a string of length *n* consisting of zeroes and ones. Consider the following operation: we choose any two adjacent positions in the string, and if one them contains 0, and the other contains 1, then we are allowed to remove these two digits from the string, obtaining a string of length *n*<=-<=2 as a result.
Now Andreid thinks about what is the minimum length of the string that can remain after applying the described operation several times (possibly, zero)? Help him to calculate this number. | First line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=2·105), the length of the string that Andreid has.
The second line contains the string of length *n* consisting only from zeros and ones. | Output the minimum length of the string that may remain after applying the described operations several times. | [
"4\n1100\n",
"5\n01010\n",
"8\n11101111\n"
] | [
"0\n",
"1\n",
"6\n"
] | In the first sample test it is possible to change the string like the following: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/10df55364c21c6e8d5da31b6ab6f6294c4fc26b3.png" style="max-width: 100.0%;max-height: 100.0%;"/>.
In the second sample test it is possible to change the string like the following: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/19ec5dcd85f0b5cf757aa076ace72df39634de2d.png" style="max-width: 100.0%;max-height: 100.0%;"/>.
In the third sample test it is possible to change the string like the following: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/dc34a159e4230375fa325555527ebc748811f188.png" style="max-width: 100.0%;max-height: 100.0%;"/>. | [
{
"input": "4\n1100",
"output": "0"
},
{
"input": "5\n01010",
"output": "1"
},
{
"input": "8\n11101111",
"output": "6"
},
{
"input": "1\n0",
"output": "1"
},
{
"input": "1\n1",
"output": "1"
},
{
"input": "2\n00",
"output": "2"
},
{
"input"... | 61 | 409,600 | -1 | 812 | |
303 | Lucky Permutation Triple | [
"constructive algorithms",
"implementation",
"math"
] | null | null | Bike is interested in permutations. A permutation of length *n* is an integer sequence such that each integer from 0 to (*n*<=-<=1) appears exactly once in it. For example, [0,<=2,<=1] is a permutation of length 3 while both [0,<=2,<=2] and [1,<=2,<=3] is not.
A permutation triple of permutations of length *n* (*a*,<=*b*,<=*c*) is called a Lucky Permutation Triple if and only if . The sign *a**i* denotes the *i*-th element of permutation *a*. The modular equality described above denotes that the remainders after dividing *a**i*<=+<=*b**i* by *n* and dividing *c**i* by *n* are equal.
Now, he has an integer *n* and wants to find a Lucky Permutation Triple. Could you please help him? | The first line contains a single integer *n* (1<=≤<=*n*<=≤<=105). | If no Lucky Permutation Triple of length *n* exists print -1.
Otherwise, you need to print three lines. Each line contains *n* space-seperated integers. The first line must contain permutation *a*, the second line — permutation *b*, the third — permutation *c*.
If there are multiple solutions, print any of them. | [
"5\n",
"2\n"
] | [
"1 4 3 2 0\n1 0 2 4 3\n2 4 0 1 3\n",
"-1\n"
] | In Sample 1, the permutation triple ([1, 4, 3, 2, 0], [1, 0, 2, 4, 3], [2, 4, 0, 1, 3]) is Lucky Permutation Triple, as following holds:
- <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/a6bf1b9b57809dbec5021f65f89616f259587c07.png" style="max-width: 100.0%;max-height: 100.0%;"/>; - <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/48cc13134296b68f459f69d78e0240859aaec702.png" style="max-width: 100.0%;max-height: 100.0%;"/>; - <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/ac44412de7b46833e90348a6b3298f9796e3977c.png" style="max-width: 100.0%;max-height: 100.0%;"/>; - <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/3825b0bb758208dda2ead1c5224c05d89ad9ab55.png" style="max-width: 100.0%;max-height: 100.0%;"/>; - <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/0a72e2da40048a507839927a211267ac01c9bf89.png" style="max-width: 100.0%;max-height: 100.0%;"/>.
In Sample 2, you can easily notice that no lucky permutation triple exists. | [
{
"input": "5",
"output": "1 4 3 2 0\n1 0 2 4 3\n2 4 0 1 3"
},
{
"input": "2",
"output": "-1"
},
{
"input": "8",
"output": "-1"
},
{
"input": "9",
"output": "0 1 2 3 4 5 6 7 8 \n0 1 2 3 4 5 6 7 8 \n0 2 4 6 8 1 3 5 7 "
},
{
"input": "2",
"output": "-1"
},
{... | 1,154 | 7,475,200 | 3 | 816 | |
88 | Keyboard | [
"implementation"
] | B. Keyboard | 1 | 256 | Vasya learns to type. He has an unusual keyboard at his disposal: it is rectangular and it has *n* rows of keys containing *m* keys in each row. Besides, the keys are of two types. Some of the keys have lowercase Latin letters on them and some of the keys work like the "Shift" key on standard keyboards, that is, they make lowercase letters uppercase.
Vasya can press one or two keys with one hand. However, he can only press two keys if the Euclidean distance between the centers of the keys does not exceed *x*. The keys are considered as squares with a side equal to 1. There are no empty spaces between neighbouring keys.
Vasya is a very lazy boy, that's why he tries to type with one hand as he eats chips with his other one. However, it is possible that some symbol can't be typed with one hand only, because the distance between it and the closest "Shift" key is strictly larger than *x*. In this case he will have to use his other hand. Having typed the symbol, Vasya returns other hand back to the chips.
You are given Vasya's keyboard and the text. Count the minimum number of times Vasya will have to use the other hand. | The first line contains three integers *n*, *m*, *x* (1<=≤<=*n*,<=*m*<=≤<=30,<=1<=≤<=*x*<=≤<=50).
Next *n* lines contain descriptions of all the keyboard keys. Each line contains the descriptions of exactly *m* keys, without spaces. The letter keys are marked with the corresponding lowercase letters. The "Shift" keys are marked with the "S" symbol.
Then follow the length of the text *q* (1<=≤<=*q*<=≤<=5·105). The last line contains the text *T*, which consists of *q* symbols, which are uppercase and lowercase Latin letters. | If Vasya can type the text, then print the minimum number of times he will have to use his other hand. Otherwise, print "-1" (without the quotes). | [
"2 2 1\nab\ncd\n1\nA\n",
"2 2 1\nab\ncd\n1\ne\n",
"2 2 1\nab\ncS\n5\nabcBA\n",
"3 9 4\nqwertyuio\nasdfghjkl\nSzxcvbnmS\n35\nTheQuIcKbRoWnFOXjummsovertHeLazYDOG\n"
] | [
"-1\n",
"-1\n",
"1\n",
"2\n"
] | In the first sample the symbol "A" is impossible to print as there's no "Shift" key on the keyboard.
In the second sample the symbol "e" is impossible to print as there's no such key on the keyboard.
In the fourth sample the symbols "T", "G" are impossible to print with one hand. The other letters that are on the keyboard can be printed. Those symbols come up in the text twice, thus, the answer is 2. | [
{
"input": "2 2 1\nab\ncd\n1\nA",
"output": "-1"
},
{
"input": "2 2 1\nab\ncd\n1\ne",
"output": "-1"
},
{
"input": "2 2 1\nab\ncS\n5\nabcBA",
"output": "1"
},
{
"input": "3 9 4\nqwertyuio\nasdfghjkl\nSzxcvbnmS\n35\nTheQuIcKbRoWnFOXjummsovertHeLazYDOG",
"output": "2"
},
... | 46 | 0 | 0 | 822 |
12 | Fruits | [
"greedy",
"implementation",
"sortings"
] | C. Fruits | 1 | 256 | The spring is coming and it means that a lot of fruits appear on the counters. One sunny day little boy Valera decided to go shopping. He made a list of *m* fruits he wanted to buy. If Valera want to buy more than one fruit of some kind, he includes it into the list several times.
When he came to the fruit stall of Ashot, he saw that the seller hadn't distributed price tags to the goods, but put all price tags on the counter. Later Ashot will attach every price tag to some kind of fruits, and Valera will be able to count the total price of all fruits from his list. But Valera wants to know now what can be the smallest total price (in case of the most «lucky» for him distribution of price tags) and the largest total price (in case of the most «unlucky» for him distribution of price tags). | The first line of the input contains two integer number *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=100) — the number of price tags (which is equal to the number of different kinds of fruits that Ashot sells) and the number of items in Valera's list. The second line contains *n* space-separated positive integer numbers. Each of them doesn't exceed 100 and stands for the price of one fruit of some kind. The following *m* lines contain names of the fruits from the list. Each name is a non-empty string of small Latin letters which length doesn't exceed 32. It is guaranteed that the number of distinct fruits from the list is less of equal to *n*. Also it is known that the seller has in stock all fruits that Valera wants to buy. | Print two numbers *a* and *b* (*a*<=≤<=*b*) — the minimum and the maximum possible sum which Valera may need to buy all fruits from his list. | [
"5 3\n4 2 1 10 5\napple\norange\nmango\n",
"6 5\n3 5 1 6 8 1\npeach\ngrapefruit\nbanana\norange\norange\n"
] | [
"7 19\n",
"11 30\n"
] | none | [
{
"input": "5 3\n4 2 1 10 5\napple\norange\nmango",
"output": "7 19"
},
{
"input": "6 5\n3 5 1 6 8 1\npeach\ngrapefruit\nbanana\norange\norange",
"output": "11 30"
},
{
"input": "2 2\n91 82\neiiofpfpmemlakcystpun\nmcnzeiiofpfpmemlakcystpunfl",
"output": "173 173"
},
{
"input"... | 31 | 0 | 3.9845 | 823 |
0 | none | [
"none"
] | null | null | Petya loves lucky numbers very much. Everybody knows that lucky numbers are positive integers whose decimal record contains only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not.
Petya has two strings *a* and *b* of the same length *n*. The strings consist only of lucky digits. Petya can perform operations of two types:
- replace any one digit from string *a* by its opposite (i.e., replace 4 by 7 and 7 by 4); - swap any pair of digits in string *a*.
Petya is interested in the minimum number of operations that are needed to make string *a* equal to string *b*. Help him with the task. | The first and the second line contains strings *a* and *b*, correspondingly. Strings *a* and *b* have equal lengths and contain only lucky digits. The strings are not empty, their length does not exceed 105. | Print on the single line the single number — the minimum number of operations needed to convert string *a* into string *b*. | [
"47\n74\n",
"774\n744\n",
"777\n444\n"
] | [
"1\n",
"1\n",
"3\n"
] | In the first sample it is enough simply to swap the first and the second digit.
In the second sample we should replace the second digit with its opposite.
In the third number we should replace all three digits with their opposites. | [
{
"input": "47\n74",
"output": "1"
},
{
"input": "774\n744",
"output": "1"
},
{
"input": "777\n444",
"output": "3"
},
{
"input": "74747474\n77777777",
"output": "4"
},
{
"input": "444444444444\n777777777777",
"output": "12"
},
{
"input": "4744744447774... | 186 | 5,017,600 | 3 | 824 | |
371 | K-Periodic Array | [
"greedy",
"implementation",
"math"
] | null | null | This task will exclusively concentrate only on the arrays where all elements equal 1 and/or 2.
Array *a* is *k*-period if its length is divisible by *k* and there is such array *b* of length *k*, that *a* is represented by array *b* written exactly times consecutively. In other words, array *a* is *k*-periodic, if it has period of length *k*.
For example, any array is *n*-periodic, where *n* is the array length. Array [2,<=1,<=2,<=1,<=2,<=1] is at the same time 2-periodic and 6-periodic and array [1,<=2,<=1,<=1,<=2,<=1,<=1,<=2,<=1] is at the same time 3-periodic and 9-periodic.
For the given array *a*, consisting only of numbers one and two, find the minimum number of elements to change to make the array *k*-periodic. If the array already is *k*-periodic, then the required value equals 0. | The first line of the input contains a pair of integers *n*, *k* (1<=≤<=*k*<=≤<=*n*<=≤<=100), where *n* is the length of the array and the value *n* is divisible by *k*. The second line contains the sequence of elements of the given array *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=2), *a**i* is the *i*-th element of the array. | Print the minimum number of array elements we need to change to make the array *k*-periodic. If the array already is *k*-periodic, then print 0. | [
"6 2\n2 1 2 2 2 1\n",
"8 4\n1 1 2 1 1 1 2 1\n",
"9 3\n2 1 1 1 2 1 1 1 2\n"
] | [
"1\n",
"0\n",
"3\n"
] | In the first sample it is enough to change the fourth element from 2 to 1, then the array changes to [2, 1, 2, 1, 2, 1].
In the second sample, the given array already is 4-periodic.
In the third sample it is enough to replace each occurrence of number two by number one. In this case the array will look as [1, 1, 1, 1, 1, 1, 1, 1, 1] — this array is simultaneously 1-, 3- and 9-periodic. | [
{
"input": "6 2\n2 1 2 2 2 1",
"output": "1"
},
{
"input": "8 4\n1 1 2 1 1 1 2 1",
"output": "0"
},
{
"input": "9 3\n2 1 1 1 2 1 1 1 2",
"output": "3"
},
{
"input": "1 1\n2",
"output": "0"
},
{
"input": "2 1\n1 1",
"output": "0"
},
{
"input": "2 2\n2 2... | 62 | 0 | 3 | 825 | |
0 | none | [
"none"
] | null | null | For a given positive integer *n* denote its *k*-rounding as the minimum positive integer *x*, such that *x* ends with *k* or more zeros in base 10 and is divisible by *n*.
For example, 4-rounding of 375 is 375·80<==<=30000. 30000 is the minimum integer such that it ends with 4 or more zeros and is divisible by 375.
Write a program that will perform the *k*-rounding of *n*. | The only line contains two integers *n* and *k* (1<=≤<=*n*<=≤<=109, 0<=≤<=*k*<=≤<=8). | Print the *k*-rounding of *n*. | [
"375 4\n",
"10000 1\n",
"38101 0\n",
"123456789 8\n"
] | [
"30000\n",
"10000\n",
"38101\n",
"12345678900000000\n"
] | none | [
{
"input": "375 4",
"output": "30000"
},
{
"input": "10000 1",
"output": "10000"
},
{
"input": "38101 0",
"output": "38101"
},
{
"input": "123456789 8",
"output": "12345678900000000"
},
{
"input": "1 0",
"output": "1"
},
{
"input": "2 0",
"output":... | 1,000 | 0 | 0 | 826 | |
776 | Molly's Chemicals | [
"binary search",
"brute force",
"data structures",
"implementation",
"math"
] | null | null | Molly Hooper has *n* different kinds of chemicals arranged in a line. Each of the chemicals has an affection value, The *i*-th of them has affection value *a**i*.
Molly wants Sherlock to fall in love with her. She intends to do this by mixing a contiguous segment of chemicals together to make a love potion with total affection value as a non-negative integer power of *k*. Total affection value of a continuous segment of chemicals is the sum of affection values of each chemical in that segment.
Help her to do so in finding the total number of such segments. | The first line of input contains two integers, *n* and *k*, the number of chemicals and the number, such that the total affection value is a non-negative power of this number *k*. (1<=≤<=*n*<=≤<=105, 1<=≤<=|*k*|<=≤<=10).
Next line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (<=-<=109<=≤<=*a**i*<=≤<=109) — affection values of chemicals. | Output a single integer — the number of valid segments. | [
"4 2\n2 2 2 2\n",
"4 -3\n3 -6 -3 12\n"
] | [
"8\n",
"3\n"
] | Do keep in mind that *k*<sup class="upper-index">0</sup> = 1.
In the first sample, Molly can get following different affection values:
- 2: segments [1, 1], [2, 2], [3, 3], [4, 4]; - 4: segments [1, 2], [2, 3], [3, 4]; - 6: segments [1, 3], [2, 4]; - 8: segments [1, 4].
Out of these, 2, 4 and 8 are powers of *k* = 2. Therefore, the answer is 8.
In the second sample, Molly can choose segments [1, 2], [3, 3], [3, 4]. | [
{
"input": "4 2\n2 2 2 2",
"output": "8"
},
{
"input": "4 -3\n3 -6 -3 12",
"output": "3"
},
{
"input": "14 -9\n-2 -4 62 53 90 41 35 21 85 74 85 57 10 39",
"output": "0"
},
{
"input": "20 9\n90 21 -6 -61 14 -21 -17 -65 -84 -75 -48 56 67 -50 16 65 -79 -61 92 85",
"output": ... | 577 | 14,745,600 | 0 | 828 | |
989 | A Tide of Riverscape | [
"constructive algorithms",
"strings"
] | null | null | "Time," Mino thinks aloud.
"What?"
"Time and tide wait for no man," explains Mino. "My name, taken from the river, always reminds me of this."
"And what are you recording?"
"You see it, tide. Everything has its own period, and I think I've figured out this one," says Mino with confidence.
Doubtfully, Kanno peeks at Mino's records.
The records are expressed as a string $s$ of characters '0', '1' and '.', where '0' denotes a low tide, '1' denotes a high tide, and '.' denotes an unknown one (either high or low).
You are to help Mino determine whether it's possible that after replacing each '.' independently with '0' or '1', a given integer $p$ is not a period of the resulting string. In case the answer is yes, please also show such a replacement to Mino.
In this problem, a positive integer $p$ is considered a period of string $s$, if for all $1 \leq i \leq \lvert s \rvert - p$, the $i$-th and $(i + p)$-th characters of $s$ are the same. Here $\lvert s \rvert$ is the length of $s$. | The first line contains two space-separated integers $n$ and $p$ ($1 \leq p \leq n \leq 2000$) — the length of the given string and the supposed period, respectively.
The second line contains a string $s$ of $n$ characters — Mino's records. $s$ only contains characters '0', '1' and '.', and contains at least one '.' character. | Output one line — if it's possible that $p$ is not a period of the resulting string, output any one of such strings; otherwise output "No" (without quotes, you can print letters in any case (upper or lower)). | [
"10 7\n1.0.1.0.1.\n",
"10 6\n1.0.1.1000\n",
"10 9\n1........1\n"
] | [
"1000100010\n",
"1001101000\n",
"No\n"
] | In the first example, $7$ is not a period of the resulting string because the $1$-st and $8$-th characters of it are different.
In the second example, $6$ is not a period of the resulting string because the $4$-th and $10$-th characters of it are different.
In the third example, $9$ is always a period because the only constraint that the first and last characters are the same is already satisfied.
Note that there are multiple acceptable answers for the first two examples, you can print any of them. | [
{
"input": "10 7\n1.0.1.0.1.",
"output": "1000100010"
},
{
"input": "10 6\n1.0.1.1000",
"output": "1001101000"
},
{
"input": "10 9\n1........1",
"output": "No"
},
{
"input": "1 1\n.",
"output": "No"
},
{
"input": "5 1\n0...1",
"output": "00001"
},
{
"i... | 109 | 0 | 3 | 829 | |
593 | 2Char | [
"brute force",
"implementation"
] | null | null | Andrew often reads articles in his favorite magazine 2Char. The main feature of these articles is that each of them uses at most two distinct letters. Andrew decided to send an article to the magazine, but as he hasn't written any article, he just decided to take a random one from magazine 26Char. However, before sending it to the magazine 2Char, he needs to adapt the text to the format of the journal. To do so, he removes some words from the chosen article, in such a way that the remaining text can be written using no more than two distinct letters.
Since the payment depends from the number of non-space characters in the article, Andrew wants to keep the words with the maximum total length. | The first line of the input contains number *n* (1<=≤<=*n*<=≤<=100) — the number of words in the article chosen by Andrew. Following are *n* lines, each of them contains one word. All the words consist only of small English letters and their total length doesn't exceed 1000. The words are not guaranteed to be distinct, in this case you are allowed to use a word in the article as many times as it appears in the input. | Print a single integer — the maximum possible total length of words in Andrew's article. | [
"4\nabb\ncacc\naaa\nbbb\n",
"5\na\na\nbcbcb\ncdecdecdecdecdecde\naaaa\n"
] | [
"9",
"6"
] | In the first sample the optimal way to choose words is {'abb', 'aaa', 'bbb'}.
In the second sample the word 'cdecdecdecdecdecde' consists of three distinct letters, and thus cannot be used in the article. The optimal answer is {'a', 'a', 'aaaa'}. | [
{
"input": "4\nabb\ncacc\naaa\nbbb",
"output": "9"
},
{
"input": "5\na\na\nbcbcb\ncdecdecdecdecdecde\naaaa",
"output": "6"
},
{
"input": "1\na",
"output": "1"
},
{
"input": "2\nz\nz",
"output": "2"
},
{
"input": "5\nabcde\nfghij\nklmno\npqrst\nuvwxy",
"output"... | 46 | 204,800 | -1 | 831 | |
405 | Gravity Flip | [
"greedy",
"implementation",
"sortings"
] | null | null | Little Chris is bored during his physics lessons (too easy), so he has built a toy box to keep himself occupied. The box is special, since it has the ability to change gravity.
There are *n* columns of toy cubes in the box arranged in a line. The *i*-th column contains *a**i* cubes. At first, the gravity in the box is pulling the cubes downwards. When Chris switches the gravity, it begins to pull all the cubes to the right side of the box. The figure shows the initial and final configurations of the cubes in the box: the cubes that have changed their position are highlighted with orange.
Given the initial configuration of the toy cubes in the box, find the amounts of cubes in each of the *n* columns after the gravity switch! | The first line of input contains an integer *n* (1<=≤<=*n*<=≤<=100), the number of the columns in the box. The next line contains *n* space-separated integer numbers. The *i*-th number *a**i* (1<=≤<=*a**i*<=≤<=100) denotes the number of cubes in the *i*-th column. | Output *n* integer numbers separated by spaces, where the *i*-th number is the amount of cubes in the *i*-th column after the gravity switch. | [
"4\n3 2 1 2\n",
"3\n2 3 8\n"
] | [
"1 2 2 3 \n",
"2 3 8 \n"
] | The first example case is shown on the figure. The top cube of the first column falls to the top of the last column; the top cube of the second column falls to the top of the third column; the middle cube of the first column falls to the top of the second column.
In the second example case the gravity switch does not change the heights of the columns. | [
{
"input": "4\n3 2 1 2",
"output": "1 2 2 3 "
},
{
"input": "3\n2 3 8",
"output": "2 3 8 "
},
{
"input": "5\n2 1 2 1 2",
"output": "1 1 2 2 2 "
},
{
"input": "1\n1",
"output": "1 "
},
{
"input": "2\n4 3",
"output": "3 4 "
},
{
"input": "6\n100 40 60 20... | 46 | 0 | 3 | 835 | |
296 | Yaroslav and Permutations | [
"greedy",
"math"
] | null | null | Yaroslav has an array that consists of *n* integers. In one second Yaroslav can swap two neighboring array elements. Now Yaroslav is wondering if he can obtain an array where any two neighboring elements would be distinct in a finite time.
Help Yaroslav. | The first line contains integer *n* (1<=≤<=*n*<=≤<=100) — the number of elements in the array. The second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=1000) — the array elements. | In the single line print "YES" (without the quotes) if Yaroslav can obtain the array he needs, and "NO" (without the quotes) otherwise. | [
"1\n1\n",
"3\n1 1 2\n",
"4\n7 7 7 7\n"
] | [
"YES\n",
"YES\n",
"NO\n"
] | In the first sample the initial array fits well.
In the second sample Yaroslav can get array: 1, 2, 1. He can swap the last and the second last elements to obtain it.
In the third sample Yarosav can't get the array he needs. | [
{
"input": "1\n1",
"output": "YES"
},
{
"input": "3\n1 1 2",
"output": "YES"
},
{
"input": "4\n7 7 7 7",
"output": "NO"
},
{
"input": "4\n479 170 465 146",
"output": "YES"
},
{
"input": "5\n996 437 605 996 293",
"output": "YES"
},
{
"input": "6\n727 53... | 122 | 2,867,200 | -1 | 837 | |
359 | Prime Number | [
"math",
"number theory"
] | null | null | Simon has a prime number *x* and an array of non-negative integers *a*1,<=*a*2,<=...,<=*a**n*.
Simon loves fractions very much. Today he wrote out number on a piece of paper. After Simon led all fractions to a common denominator and summed them up, he got a fraction: , where number *t* equals *x**a*1<=+<=*a*2<=+<=...<=+<=*a**n*. Now Simon wants to reduce the resulting fraction.
Help him, find the greatest common divisor of numbers *s* and *t*. As GCD can be rather large, print it as a remainder after dividing it by number 1000000007 (109<=+<=7). | The first line contains two positive integers *n* and *x* (1<=≤<=*n*<=≤<=105, 2<=≤<=*x*<=≤<=109) — the size of the array and the prime number.
The second line contains *n* space-separated integers *a*1,<=*a*2,<=...,<=*a**n* (0<=≤<=*a*1<=≤<=*a*2<=≤<=...<=≤<=*a**n*<=≤<=109). | Print a single number — the answer to the problem modulo 1000000007 (109<=+<=7). | [
"2 2\n2 2\n",
"3 3\n1 2 3\n",
"2 2\n29 29\n",
"4 5\n0 0 0 0\n"
] | [
"8\n",
"27\n",
"73741817\n",
"1\n"
] | In the first sample <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/7745f7cc87c6c5f753e3414fad9baa3b1e3fea48.png" style="max-width: 100.0%;max-height: 100.0%;"/>. Thus, the answer to the problem is 8.
In the second sample, <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/acb3d7990f024100be499bcb59828fa6e23a867d.png" style="max-width: 100.0%;max-height: 100.0%;"/>. The answer to the problem is 27, as 351 = 13·27, 729 = 27·27.
In the third sample the answer to the problem is 1073741824 *mod* 1000000007 = 73741817.
In the fourth sample <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/05a5fca3fb4690369838ff6dfeda521c959aa937.png" style="max-width: 100.0%;max-height: 100.0%;"/>. Thus, the answer to the problem is 1. | [
{
"input": "2 2\n2 2",
"output": "8"
},
{
"input": "3 3\n1 2 3",
"output": "27"
},
{
"input": "2 2\n29 29",
"output": "73741817"
},
{
"input": "4 5\n0 0 0 0",
"output": "1"
},
{
"input": "1 2\n1000000000",
"output": "1"
},
{
"input": "26 2\n0 0 0 0 0 0... | 46 | 0 | 0 | 838 | |
841 | Generous Kefa | [
"brute force",
"implementation"
] | null | null | One day Kefa found *n* baloons. For convenience, we denote color of *i*-th baloon as *s**i* — lowercase letter of the Latin alphabet. Also Kefa has *k* friends. Friend will be upset, If he get two baloons of the same color. Kefa want to give out all baloons to his friends. Help Kefa to find out, can he give out all his baloons, such that no one of his friens will be upset — print «YES», if he can, and «NO», otherwise. Note, that Kefa's friend will not upset, if he doesn't get baloons at all. | The first line contains two integers *n* and *k* (1<=≤<=*n*,<=*k*<=≤<=100) — the number of baloons and friends.
Next line contains string *s* — colors of baloons. | Answer to the task — «YES» or «NO» in a single line.
You can choose the case (lower or upper) for each letter arbitrary. | [
"4 2\naabb\n",
"6 3\naacaab\n"
] | [
"YES\n",
"NO\n"
] | In the first sample Kefa can give 1-st and 3-rd baloon to the first friend, and 2-nd and 4-th to the second.
In the second sample Kefa needs to give to all his friends baloons of color a, but one baloon will stay, thats why answer is «NO». | [
{
"input": "4 2\naabb",
"output": "YES"
},
{
"input": "6 3\naacaab",
"output": "NO"
},
{
"input": "2 2\nlu",
"output": "YES"
},
{
"input": "5 3\novvoo",
"output": "YES"
},
{
"input": "36 13\nbzbzcffczzcbcbzzfzbbfzfzzbfbbcbfccbf",
"output": "YES"
},
{
"... | 140 | 2,150,400 | 3 | 839 | |
952 | A Map of the Cat | [
"brute force",
"interactive"
] | null | null | If you have ever interacted with a cat, you have probably noticed that they are quite particular about how to pet them. Here is an approximate map of a normal cat.
However, some cats won't tolerate this nonsense from the humans. Here is a map of a grumpy cat.
You have met a cat. Can you figure out whether it's normal or grumpy? | none | none | [] | [] | Please make sure to use the stream flushing operation after each query in order not to leave part of your output in some buffer. | [
{
"input": "5 0 1 2 5 3 5 4 5 5",
"output": "Correct answer 'normal'"
},
{
"input": "5 5 5 6 6 7 8 9 10 11",
"output": "Correct answer 'grumpy'"
},
{
"input": "10 6 5 7 5 6 11 5 8 9",
"output": "Correct answer 'grumpy'"
},
{
"input": "7 10 8 9 6 5 5 11 5 6",
"output": "Co... | 93 | 0 | 0 | 841 | |
746 | Compote | [
"implementation",
"math"
] | null | null | Nikolay has *a* lemons, *b* apples and *c* pears. He decided to cook a compote. According to the recipe the fruits should be in the ratio 1:<=2:<=4. It means that for each lemon in the compote should be exactly 2 apples and exactly 4 pears. You can't crumble up, break up or cut these fruits into pieces. These fruits — lemons, apples and pears — should be put in the compote as whole fruits.
Your task is to determine the maximum total number of lemons, apples and pears from which Nikolay can cook the compote. It is possible that Nikolay can't use any fruits, in this case print 0. | The first line contains the positive integer *a* (1<=≤<=*a*<=≤<=1000) — the number of lemons Nikolay has.
The second line contains the positive integer *b* (1<=≤<=*b*<=≤<=1000) — the number of apples Nikolay has.
The third line contains the positive integer *c* (1<=≤<=*c*<=≤<=1000) — the number of pears Nikolay has. | Print the maximum total number of lemons, apples and pears from which Nikolay can cook the compote. | [
"2\n5\n7\n",
"4\n7\n13\n",
"2\n3\n2\n"
] | [
"7\n",
"21\n",
"0\n"
] | In the first example Nikolay can use 1 lemon, 2 apples and 4 pears, so the answer is 1 + 2 + 4 = 7.
In the second example Nikolay can use 3 lemons, 6 apples and 12 pears, so the answer is 3 + 6 + 12 = 21.
In the third example Nikolay don't have enough pears to cook any compote, so the answer is 0. | [
{
"input": "2\n5\n7",
"output": "7"
},
{
"input": "4\n7\n13",
"output": "21"
},
{
"input": "2\n3\n2",
"output": "0"
},
{
"input": "1\n1\n1",
"output": "0"
},
{
"input": "1\n2\n4",
"output": "7"
},
{
"input": "1000\n1000\n1000",
"output": "1750"
}... | 109 | 0 | 3 | 844 | |
61 | Capture Valerian | [
"math"
] | C. Capture Valerian | 2 | 256 | It's now 260 AD. Shapur, being extremely smart, became the King of Persia. He is now called Shapur, His majesty King of kings of Iran and Aniran.
Recently the Romans declared war on Persia. They dreamed to occupy Armenia. In the recent war, the Romans were badly defeated. Now their senior army general, Philip is captured by Shapur and Shapur is now going to capture Valerian, the Roman emperor.
Being defeated, the cowardly Valerian hid in a room at the top of one of his castles. To capture him, Shapur has to open many doors. Fortunately Valerian was too scared to make impenetrable locks for the doors.
Each door has 4 parts. The first part is an integer number *a*. The second part is either an integer number *b* or some really odd sign which looks like R. The third one is an integer *c* and the fourth part is empty! As if it was laid for writing something. Being extremely gifted, after opening the first few doors, Shapur found out the secret behind the locks.
*c* is an integer written in base *a*, to open the door we should write it in base *b*. The only bad news is that this R is some sort of special numbering system that is used only in Roman empire, so opening the doors is not just a piece of cake!
Here's an explanation of this really weird number system that even doesn't have zero:
Roman numerals are based on seven symbols: a stroke (identified with the letter I) for a unit, a chevron (identified with the letter V) for a five, a cross-stroke (identified with the letter X) for a ten, a C (identified as an abbreviation of Centum) for a hundred, etc.:
- I=1- V=5- X=10- L=50- C=100- D=500- M=1000
Symbols are iterated to produce multiples of the decimal (1, 10, 100, 1,<=000) values, with V, L, D substituted for a multiple of five, and the iteration continuing: I 1, II 2, III 3, V 5, VI 6, VII 7, etc., and the same for other bases: X 10, XX 20, XXX 30, L 50, LXXX 80; CC 200, DCC 700, etc. At the fourth and ninth iteration, a subtractive principle must be employed, with the base placed before the higher base: IV 4, IX 9, XL 40, XC 90, CD 400, CM 900.
Also in bases greater than 10 we use A for 10, B for 11, etc.
Help Shapur capture Valerian and bring peace back to Persia, especially Armenia. | The first line contains two integers *a* and *b* (2<=≤<=*a*,<=*b*<=≤<=25). Only *b* may be replaced by an R which indicates Roman numbering system.
The next line contains a single non-negative integer *c* in base *a* which may contain leading zeros but its length doesn't exceed 103.
It is guaranteed that if we have Roman numerals included the number would be less than or equal to 300010 and it won't be 0. In any other case the number won't be greater than 101510. | Write a single line that contains integer *c* in base *b*. You must omit leading zeros. | [
"10 2\n1\n",
"16 R\n5\n",
"5 R\n4\n",
"2 2\n1111001\n",
"12 13\nA\n"
] | [
"1\n",
"V\n",
"IV\n",
"1111001\n",
"A\n"
] | You can find more information about roman numerals here: http://en.wikipedia.org/wiki/Roman_numerals | [
{
"input": "10 2\n1",
"output": "1"
},
{
"input": "16 R\n5",
"output": "V"
},
{
"input": "5 R\n4",
"output": "IV"
},
{
"input": "2 2\n1111001",
"output": "1111001"
},
{
"input": "12 13\nA",
"output": "A"
},
{
"input": "6 7\n12345",
"output": "5303"... | 124 | 307,200 | 3.968428 | 846 |
862 | Mahmoud and Ehab and the xor | [
"constructive algorithms"
] | null | null | Mahmoud and Ehab are on the third stage of their adventures now. As you know, Dr. Evil likes sets. This time he won't show them any set from his large collection, but will ask them to create a new set to replenish his beautiful collection of sets.
Dr. Evil has his favorite evil integer *x*. He asks Mahmoud and Ehab to find a set of *n* distinct non-negative integers such the bitwise-xor sum of the integers in it is exactly *x*. Dr. Evil doesn't like big numbers, so any number in the set shouldn't be greater than 106. | The only line contains two integers *n* and *x* (1<=≤<=*n*<=≤<=105, 0<=≤<=*x*<=≤<=105) — the number of elements in the set and the desired bitwise-xor, respectively. | If there is no such set, print "NO" (without quotes).
Otherwise, on the first line print "YES" (without quotes) and on the second line print *n* distinct integers, denoting the elements in the set is any order. If there are multiple solutions you can print any of them. | [
"5 5\n",
"3 6\n"
] | [
"YES\n1 2 4 5 7",
"YES\n1 2 5"
] | You can read more about the bitwise-xor operation here: [https://en.wikipedia.org/wiki/Bitwise_operation#XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR)
For the first sample <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/eb8ccd05d3a7a41eff93c98f79d158cf85e702f9.png" style="max-width: 100.0%;max-height: 100.0%;"/>.
For the second sample <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/d05d19f05b03f8ac89b7f86ef830eeccc0050c42.png" style="max-width: 100.0%;max-height: 100.0%;"/>. | [
{
"input": "5 5",
"output": "YES\n1 2 131072 131078 0 "
},
{
"input": "3 6",
"output": "YES\n131072 131078 0 "
},
{
"input": "3 0",
"output": "YES\n393216 131072 262144"
},
{
"input": "1 0",
"output": "YES\n0"
},
{
"input": "3 3",
"output": "YES\n131072 131075... | 46 | 0 | 0 | 848 | |
31 | Sysadmin Bob | [
"greedy",
"implementation",
"strings"
] | B. Sysadmin Bob | 0 | 256 | Email address in Berland is a string of the form *A*@*B*, where *A* and *B* are arbitrary strings consisting of small Latin letters.
Bob is a system administrator in «Bersoft» company. He keeps a list of email addresses of the company's staff. This list is as a large string, where all addresses are written in arbitrary order, separated by commas. The same address can be written more than once.
Suddenly, because of unknown reasons, all commas in Bob's list disappeared. Now Bob has a string, where all addresses are written one after another without any separators, and there is impossible to determine, where the boundaries between addresses are. Unfortunately, on the same day his chief asked him to bring the initial list of addresses. Now Bob wants to disjoin addresses in some valid way. Help him to do that. | The first line contains the list of addresses without separators. The length of this string is between 1 and 200, inclusive. The string consists only from small Latin letters and characters «@». | If there is no list of the valid (according to the Berland rules) email addresses such that after removing all commas it coincides with the given string, output No solution. In the other case, output the list. The same address can be written in this list more than once. If there are several solutions, output any of them. | [
"a@aa@a\n",
"a@a@a\n",
"@aa@a\n"
] | [
"a@a,a@a\n",
"No solution\n",
"No solution\n"
] | none | [
{
"input": "a@aa@a",
"output": "a@a,a@a"
},
{
"input": "a@a@a",
"output": "No solution"
},
{
"input": "@aa@a",
"output": "No solution"
},
{
"input": "aba@caba@daba",
"output": "aba@c,aba@daba"
},
{
"input": "asd@qwasd@qwasd@qwasd@qwasd@qw",
"output": "asd@q,wa... | 31 | 6,963,200 | 0 | 849 |
918 | Eleven | [
"brute force",
"implementation"
] | null | null | Eleven wants to choose a new name for herself. As a bunch of geeks, her friends suggested an algorithm to choose a name for her. Eleven wants her name to have exactly *n* characters.
Her friend suggested that her name should only consist of uppercase and lowercase letters 'O'. More precisely, they suggested that the *i*-th letter of her name should be 'O' (uppercase) if *i* is a member of Fibonacci sequence, and 'o' (lowercase) otherwise. The letters in the name are numbered from 1 to *n*. Fibonacci sequence is the sequence *f* where
- *f*1<==<=1, - *f*2<==<=1, - *f**n*<==<=*f**n*<=-<=2<=+<=*f**n*<=-<=1 (*n*<=><=2).
As her friends are too young to know what Fibonacci sequence is, they asked you to help Eleven determine her new name. | The first and only line of input contains an integer *n* (1<=≤<=*n*<=≤<=1000). | Print Eleven's new name on the first and only line of output. | [
"8\n",
"15\n"
] | [
"OOOoOooO\n",
"OOOoOooOooooOoo\n"
] | none | [
{
"input": "8",
"output": "OOOoOooO"
},
{
"input": "15",
"output": "OOOoOooOooooOoo"
},
{
"input": "85",
"output": "OOOoOooOooooOoooooooOooooooooooooOooooooooooooooooooooOoooooooooooooooooooooooooooooo"
},
{
"input": "381",
"output": "OOOoOooOooooOoooooooOooooooooooooOooo... | 109 | 0 | 3 | 850 | |
830 | Office Keys | [
"binary search",
"brute force",
"dp",
"greedy",
"sortings"
] | null | null | There are *n* people and *k* keys on a straight line. Every person wants to get to the office which is located on the line as well. To do that, he needs to reach some point with a key, take the key and then go to the office. Once a key is taken by somebody, it couldn't be taken by anybody else.
You are to determine the minimum time needed for all *n* people to get to the office with keys. Assume that people move a unit distance per 1 second. If two people reach a key at the same time, only one of them can take the key. A person can pass through a point with a key without taking it. | The first line contains three integers *n*, *k* and *p* (1<=≤<=*n*<=≤<=1<=000, *n*<=≤<=*k*<=≤<=2<=000, 1<=≤<=*p*<=≤<=109) — the number of people, the number of keys and the office location.
The second line contains *n* distinct integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=109) — positions in which people are located initially. The positions are given in arbitrary order.
The third line contains *k* distinct integers *b*1,<=*b*2,<=...,<=*b**k* (1<=≤<=*b**j*<=≤<=109) — positions of the keys. The positions are given in arbitrary order.
Note that there can't be more than one person or more than one key in the same point. A person and a key can be located in the same point. | Print the minimum time (in seconds) needed for all *n* to reach the office with keys. | [
"2 4 50\n20 100\n60 10 40 80\n",
"1 2 10\n11\n15 7\n"
] | [
"50\n",
"7\n"
] | In the first example the person located at point 20 should take the key located at point 40 and go with it to the office located at point 50. He spends 30 seconds. The person located at point 100 can take the key located at point 80 and go to the office with it. He spends 50 seconds. Thus, after 50 seconds everybody is in office with keys. | [
{
"input": "2 4 50\n20 100\n60 10 40 80",
"output": "50"
},
{
"input": "1 2 10\n11\n15 7",
"output": "7"
},
{
"input": "2 5 15\n10 4\n29 23 21 22 26",
"output": "23"
},
{
"input": "3 10 1500\n106 160 129\n1333 1532 1181 1091 1656 1698 1291 1741 1242 1163",
"output": "1394... | 62 | 0 | 0 | 851 | |
8 | Obsession with Robots | [
"constructive algorithms",
"graphs",
"implementation"
] | B. Obsession with Robots | 2 | 64 | The whole world got obsessed with robots,and to keep pace with the progress, great Berland's programmer Draude decided to build his own robot. He was working hard at the robot. He taught it to walk the shortest path from one point to another, to record all its movements, but like in many Draude's programs, there was a bug — the robot didn't always walk the shortest path. Fortunately, the robot recorded its own movements correctly. Now Draude wants to find out when his robot functions wrong. Heh, if Draude only remembered the map of the field, where he tested the robot, he would easily say if the robot walked in the right direction or not. But the field map was lost never to be found, that's why he asks you to find out if there exist at least one map, where the path recorded by the robot is the shortest.
The map is an infinite checkered field, where each square is either empty, or contains an obstruction. It is also known that the robot never tries to run into the obstruction. By the recorded robot's movements find out if there exist at least one such map, that it is possible to choose for the robot a starting square (the starting square should be empty) such that when the robot moves from this square its movements coincide with the recorded ones (the robot doesn't run into anything, moving along empty squares only), and the path from the starting square to the end one is the shortest.
In one movement the robot can move into the square (providing there are no obstrutions in this square) that has common sides with the square the robot is currently in. | The first line of the input file contains the recording of the robot's movements. This recording is a non-empty string, consisting of uppercase Latin letters L, R, U and D, standing for movements left, right, up and down respectively. The length of the string does not exceed 100. | In the first line output the only word OK (if the above described map exists), or BUG (if such a map does not exist). | [
"LLUUUR\n",
"RRUULLDD\n"
] | [
"OK\n",
"BUG\n"
] | none | [
{
"input": "LLUUUR",
"output": "OK"
},
{
"input": "RRUULLDD",
"output": "BUG"
},
{
"input": "L",
"output": "OK"
},
{
"input": "R",
"output": "OK"
},
{
"input": "R",
"output": "OK"
},
{
"input": "RR",
"output": "OK"
},
{
"input": "DL",
"... | 248 | 20,172,800 | 0 | 854 |
837 | Flag of Berland | [
"brute force",
"implementation"
] | null | null | The flag of Berland is such rectangular field *n*<=×<=*m* that satisfies following conditions:
- Flag consists of three colors which correspond to letters 'R', 'G' and 'B'. - Flag consists of three equal in width and height stripes, parralel to each other and to sides of the flag. Each stripe has exactly one color. - Each color should be used in exactly one stripe.
You are given a field *n*<=×<=*m*, consisting of characters 'R', 'G' and 'B'. Output "YES" (without quotes) if this field corresponds to correct flag of Berland. Otherwise, print "NO" (without quotes). | The first line contains two integer numbers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=100) — the sizes of the field.
Each of the following *n* lines consisting of *m* characters 'R', 'G' and 'B' — the description of the field. | Print "YES" (without quotes) if the given field corresponds to correct flag of Berland . Otherwise, print "NO" (without quotes). | [
"6 5\nRRRRR\nRRRRR\nBBBBB\nBBBBB\nGGGGG\nGGGGG\n",
"4 3\nBRG\nBRG\nBRG\nBRG\n",
"6 7\nRRRGGGG\nRRRGGGG\nRRRGGGG\nRRRBBBB\nRRRBBBB\nRRRBBBB\n",
"4 4\nRRRR\nRRRR\nBBBB\nGGGG\n"
] | [
"YES\n",
"YES\n",
"NO\n",
"NO\n"
] | The field in the third example doesn't have three parralel stripes.
Rows of the field in the fourth example are parralel to each other and to borders. But they have different heights — 2, 1 and 1. | [
{
"input": "6 5\nRRRRR\nRRRRR\nBBBBB\nBBBBB\nGGGGG\nGGGGG",
"output": "YES"
},
{
"input": "4 3\nBRG\nBRG\nBRG\nBRG",
"output": "YES"
},
{
"input": "6 7\nRRRGGGG\nRRRGGGG\nRRRGGGG\nRRRBBBB\nRRRBBBB\nRRRBBBB",
"output": "NO"
},
{
"input": "4 4\nRRRR\nRRRR\nBBBB\nGGGG",
"out... | 62 | 204,800 | -1 | 855 | |
697 | Pineapple Incident | [
"implementation",
"math"
] | null | null | Ted has a pineapple. This pineapple is able to bark like a bulldog! At time *t* (in seconds) it barks for the first time. Then every *s* seconds after it, it barks twice with 1 second interval. Thus it barks at times *t*, *t*<=+<=*s*, *t*<=+<=*s*<=+<=1, *t*<=+<=2*s*, *t*<=+<=2*s*<=+<=1, etc.
Barney woke up in the morning and wants to eat the pineapple, but he can't eat it when it's barking. Barney plans to eat it at time *x* (in seconds), so he asked you to tell him if it's gonna bark at that time. | The first and only line of input contains three integers *t*, *s* and *x* (0<=≤<=*t*,<=*x*<=≤<=109, 2<=≤<=*s*<=≤<=109) — the time the pineapple barks for the first time, the pineapple barking interval, and the time Barney wants to eat the pineapple respectively. | Print a single "YES" (without quotes) if the pineapple will bark at time *x* or a single "NO" (without quotes) otherwise in the only line of output. | [
"3 10 4\n",
"3 10 3\n",
"3 8 51\n",
"3 8 52\n"
] | [
"NO\n",
"YES\n",
"YES\n",
"YES\n"
] | In the first and the second sample cases pineapple will bark at moments 3, 13, 14, ..., so it won't bark at the moment 4 and will bark at the moment 3.
In the third and fourth sample cases pineapple will bark at moments 3, 11, 12, 19, 20, 27, 28, 35, 36, 43, 44, 51, 52, 59, ..., so it will bark at both moments 51 and 52. | [
{
"input": "3 10 4",
"output": "NO"
},
{
"input": "3 10 3",
"output": "YES"
},
{
"input": "3 8 51",
"output": "YES"
},
{
"input": "3 8 52",
"output": "YES"
},
{
"input": "456947336 740144 45",
"output": "NO"
},
{
"input": "33 232603 599417964",
"ou... | 31 | 0 | -1 | 858 | |
493 | Vasya and Football | [
"implementation"
] | null | null | Vasya has started watching football games. He has learned that for some fouls the players receive yellow cards, and for some fouls they receive red cards. A player who receives the second yellow card automatically receives a red card.
Vasya is watching a recorded football match now and makes notes of all the fouls that he would give a card for. Help Vasya determine all the moments in time when players would be given red cards if Vasya were the judge. For each player, Vasya wants to know only the first moment of time when he would receive a red card from Vasya. | The first line contains the name of the team playing at home. The second line contains the name of the team playing away. Both lines are not empty. The lengths of both lines do not exceed 20. Each line contains only of large English letters. The names of the teams are distinct.
Next follows number *n* (1<=≤<=*n*<=≤<=90) — the number of fouls.
Each of the following *n* lines contains information about a foul in the following form:
- first goes number *t* (1<=≤<=*t*<=≤<=90) — the minute when the foul occurs; - then goes letter "h" or letter "a" — if the letter is "h", then the card was given to a home team player, otherwise the card was given to an away team player; - then goes the player's number *m* (1<=≤<=*m*<=≤<=99); - then goes letter "y" or letter "r" — if the letter is "y", that means that the yellow card was given, otherwise the red card was given.
The players from different teams can have the same number. The players within one team have distinct numbers. The fouls go chronologically, no two fouls happened at the same minute. | For each event when a player received his first red card in a chronological order print a string containing the following information:
- The name of the team to which the player belongs; - the player's number in his team; - the minute when he received the card.
If no player received a card, then you do not need to print anything.
It is possible case that the program will not print anything to the output (if there were no red cards). | [
"MC\nCSKA\n9\n28 a 3 y\n62 h 25 y\n66 h 42 y\n70 h 25 y\n77 a 4 y\n79 a 25 y\n82 h 42 r\n89 h 16 y\n90 a 13 r\n"
] | [
"MC 25 70\nMC 42 82\nCSKA 13 90\n"
] | none | [
{
"input": "MC\nCSKA\n9\n28 a 3 y\n62 h 25 y\n66 h 42 y\n70 h 25 y\n77 a 4 y\n79 a 25 y\n82 h 42 r\n89 h 16 y\n90 a 13 r",
"output": "MC 25 70\nMC 42 82\nCSKA 13 90"
},
{
"input": "REAL\nBARCA\n3\n27 h 7 y\n44 a 10 y\n87 h 3 r",
"output": "REAL 3 87"
},
{
"input": "MASFF\nSAFBDSRG\n5\n1 ... | 155 | 5,836,800 | 3 | 859 | |
269 | Greenhouse Effect | [
"dp"
] | null | null | Emuskald is an avid horticulturist and owns the world's longest greenhouse — it is effectively infinite in length.
Over the years Emuskald has cultivated *n* plants in his greenhouse, of *m* different plant species numbered from 1 to *m*. His greenhouse is very narrow and can be viewed as an infinite line, with each plant occupying a single point on that line.
Emuskald has discovered that each species thrives at a different temperature, so he wants to arrange *m*<=-<=1 borders that would divide the greenhouse into *m* sections numbered from 1 to *m* from left to right with each section housing a single species. He is free to place the borders, but in the end all of the *i*-th species plants must reside in *i*-th section from the left.
Of course, it is not always possible to place the borders in such way, so Emuskald needs to replant some of his plants. He can remove each plant from its position and place it anywhere in the greenhouse (at any real coordinate) with no plant already in it. Since replanting is a lot of stress for the plants, help Emuskald find the minimum number of plants he has to replant to be able to place the borders. | The first line of input contains two space-separated integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=5000, *n*<=≥<=*m*), the number of plants and the number of different species. Each of the following *n* lines contain two space-separated numbers: one integer number *s**i* (1<=≤<=*s**i*<=≤<=*m*), and one real number *x**i* (0<=≤<=*x**i*<=≤<=109), the species and position of the *i*-th plant. Each *x**i* will contain no more than 6 digits after the decimal point.
It is guaranteed that all *x**i* are different; there is at least one plant of each species; the plants are given in order "from left to the right", that is in the ascending order of their *x**i* coordinates (*x**i*<=<<=*x**i*<=+<=1,<=1<=≤<=*i*<=<<=*n*). | Output a single integer — the minimum number of plants to be replanted. | [
"3 2\n2 1\n1 2.0\n1 3.100\n",
"3 3\n1 5.0\n2 5.5\n3 6.0\n",
"6 3\n1 14.284235\n2 17.921382\n1 20.328172\n3 20.842331\n1 25.790145\n1 27.204125\n"
] | [
"1\n",
"0\n",
"2\n"
] | In the first test case, Emuskald can replant the first plant to the right of the last plant, so the answer is 1.
In the second test case, the species are already in the correct order, so no replanting is needed. | [
{
"input": "3 2\n2 1\n1 2.0\n1 3.100",
"output": "1"
},
{
"input": "3 3\n1 5.0\n2 5.5\n3 6.0",
"output": "0"
},
{
"input": "6 3\n1 14.284235\n2 17.921382\n1 20.328172\n3 20.842331\n1 25.790145\n1 27.204125",
"output": "2"
},
{
"input": "1 1\n1 0",
"output": "0"
},
{
... | 124 | 4,608,000 | 0 | 860 | |
4 | Before an Exam | [
"constructive algorithms",
"greedy"
] | B. Before an Exam | 0 | 64 | Tomorrow Peter has a Biology exam. He does not like this subject much, but *d* days ago he learnt that he would have to take this exam. Peter's strict parents made him prepare for the exam immediately, for this purpose he has to study not less than *minTime**i* and not more than *maxTime**i* hours per each *i*-th day. Moreover, they warned Peter that a day before the exam they would check how he has followed their instructions.
So, today is the day when Peter's parents ask him to show the timetable of his preparatory studies. But the boy has counted only the sum of hours *sumTime* spent him on preparation, and now he wants to know if he can show his parents a timetable *sсhedule* with *d* numbers, where each number *sсhedule**i* stands for the time in hours spent by Peter each *i*-th day on biology studies, and satisfying the limitations imposed by his parents, and at the same time the sum total of all *schedule**i* should equal to *sumTime*. | The first input line contains two integer numbers *d*,<=*sumTime* (1<=≤<=*d*<=≤<=30,<=0<=≤<=*sumTime*<=≤<=240) — the amount of days, during which Peter studied, and the total amount of hours, spent on preparation. Each of the following *d* lines contains two integer numbers *minTime**i*,<=*maxTime**i* (0<=≤<=*minTime**i*<=≤<=*maxTime**i*<=≤<=8), separated by a space — minimum and maximum amount of hours that Peter could spent in the *i*-th day. | In the first line print YES, and in the second line print *d* numbers (separated by a space), each of the numbers — amount of hours, spent by Peter on preparation in the corresponding day, if he followed his parents' instructions; or print NO in the unique line. If there are many solutions, print any of them. | [
"1 48\n5 7\n",
"2 5\n0 1\n3 5\n"
] | [
"NO\n",
"YES\n1 4 "
] | none | [
{
"input": "1 48\n5 7",
"output": "NO"
},
{
"input": "2 5\n0 1\n3 5",
"output": "YES\n1 4 "
},
{
"input": "1 1\n5 6",
"output": "NO"
},
{
"input": "1 4\n2 4",
"output": "YES\n4 "
},
{
"input": "2 5\n4 6\n0 0",
"output": "YES\n5 0 "
},
{
"input": "27 97... | 77 | 2,867,200 | -1 | 861 |
755 | PolandBall and Hypothesis | [
"brute force",
"graphs",
"math",
"number theory"
] | null | null | PolandBall is a young, clever Ball. He is interested in prime numbers. He has stated a following hypothesis: "There exists such a positive integer *n* that for each positive integer *m* number *n*·*m*<=+<=1 is a prime number".
Unfortunately, PolandBall is not experienced yet and doesn't know that his hypothesis is incorrect. Could you prove it wrong? Write a program that finds a counterexample for any *n*. | The only number in the input is *n* (1<=≤<=*n*<=≤<=1000) — number from the PolandBall's hypothesis. | Output such *m* that *n*·*m*<=+<=1 is not a prime number. Your answer will be considered correct if you output any suitable *m* such that 1<=≤<=*m*<=≤<=103. It is guaranteed the the answer exists. | [
"3\n",
"4\n"
] | [
"1",
"2"
] | A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.
For the first sample testcase, 3·1 + 1 = 4. We can output 1.
In the second sample testcase, 4·1 + 1 = 5. We cannot output 1 because 5 is prime. However, *m* = 2 is okay since 4·2 + 1 = 9, which is not a prime number. | [
{
"input": "3",
"output": "1"
},
{
"input": "4",
"output": "2"
},
{
"input": "10",
"output": "2"
},
{
"input": "153",
"output": "1"
},
{
"input": "1000",
"output": "1"
},
{
"input": "1",
"output": "3"
},
{
"input": "2",
"output": "4"
... | 78 | 0 | 3 | 862 | |
579 | Raising Bacteria | [
"bitmasks"
] | null | null | You are a lover of bacteria. You want to raise some bacteria in a box.
Initially, the box is empty. Each morning, you can put any number of bacteria into the box. And each night, every bacterium in the box will split into two bacteria. You hope to see exactly *x* bacteria in the box at some moment.
What is the minimum number of bacteria you need to put into the box across those days? | The only line containing one integer *x* (1<=≤<=*x*<=≤<=109). | The only line containing one integer: the answer. | [
"5\n",
"8\n"
] | [
"2\n",
"1\n"
] | For the first sample, we can add one bacterium in the box in the first day morning and at the third morning there will be 4 bacteria in the box. Now we put one more resulting 5 in the box. We added 2 bacteria in the process so the answer is 2.
For the second sample, we can put one in the first morning and in the 4-th morning there will be 8 in the box. So the answer is 1. | [
{
"input": "5",
"output": "2"
},
{
"input": "8",
"output": "1"
},
{
"input": "536870911",
"output": "29"
},
{
"input": "1",
"output": "1"
},
{
"input": "343000816",
"output": "14"
},
{
"input": "559980448",
"output": "12"
},
{
"input": "697... | 46 | 0 | 3 | 865 | |
669 | Little Artem and Presents | [
"math"
] | null | null | Little Artem got *n* stones on his birthday and now wants to give some of them to Masha. He knows that Masha cares more about the fact of receiving the present, rather than the value of that present, so he wants to give her stones as many times as possible. However, Masha remembers the last present she received, so Artem can't give her the same number of stones twice in a row. For example, he can give her 3 stones, then 1 stone, then again 3 stones, but he can't give her 3 stones and then again 3 stones right after that.
How many times can Artem give presents to Masha? | The only line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=109) — number of stones Artem received on his birthday. | Print the maximum possible number of times Artem can give presents to Masha. | [
"1\n",
"2\n",
"3\n",
"4\n"
] | [
"1\n",
"1\n",
"2\n",
"3\n"
] | In the first sample, Artem can only give 1 stone to Masha.
In the second sample, Atrem can give Masha 1 or 2 stones, though he can't give her 1 stone two times.
In the third sample, Atrem can first give Masha 2 stones, a then 1 more stone.
In the fourth sample, Atrem can first give Masha 1 stone, then 2 stones, and finally 1 stone again. | [
{
"input": "1",
"output": "1"
},
{
"input": "2",
"output": "1"
},
{
"input": "3",
"output": "2"
},
{
"input": "4",
"output": "3"
},
{
"input": "100",
"output": "67"
},
{
"input": "101",
"output": "67"
},
{
"input": "102",
"output": "68"... | 15 | 4,608,000 | 0 | 867 | |
1,009 | Game Shopping | [
"implementation"
] | null | null | Maxim wants to buy some games at the local game shop. There are $n$ games in the shop, the $i$-th game costs $c_i$.
Maxim has a wallet which can be represented as an array of integers. His wallet contains $m$ bills, the $j$-th bill has value $a_j$.
Games in the shop are ordered from left to right, Maxim tries to buy every game in that order.
When Maxim stands at the position $i$ in the shop, he takes the first bill from his wallet (if his wallet is empty then he proceeds to the next position immediately) and tries to buy the $i$-th game using this bill. After Maxim tried to buy the $n$-th game, he leaves the shop.
Maxim buys the $i$-th game if and only if the value of the first bill (which he takes) from his wallet is greater or equal to the cost of the $i$-th game. If he successfully buys the $i$-th game, the first bill from his wallet disappears and the next bill becomes first. Otherwise Maxim leaves the first bill in his wallet (this bill still remains the first one) and proceeds to the next game.
For example, for array $c = [2, 4, 5, 2, 4]$ and array $a = [5, 3, 4, 6]$ the following process takes place: Maxim buys the first game using the first bill (its value is $5$), the bill disappears, after that the second bill (with value $3$) becomes the first one in Maxim's wallet, then Maxim doesn't buy the second game because $c_2 > a_2$, the same with the third game, then he buys the fourth game using the bill of value $a_2$ (the third bill becomes the first one in Maxim's wallet) and buys the fifth game using the bill of value $a_3$.
Your task is to get the number of games Maxim will buy. | The first line of the input contains two integers $n$ and $m$ ($1 \le n, m \le 1000$) — the number of games and the number of bills in Maxim's wallet.
The second line of the input contains $n$ integers $c_1, c_2, \dots, c_n$ ($1 \le c_i \le 1000$), where $c_i$ is the cost of the $i$-th game.
The third line of the input contains $m$ integers $a_1, a_2, \dots, a_m$ ($1 \le a_j \le 1000$), where $a_j$ is the value of the $j$-th bill from the Maxim's wallet. | Print a single integer — the number of games Maxim will buy. | [
"5 4\n2 4 5 2 4\n5 3 4 6\n",
"5 2\n20 40 50 20 40\n19 20\n",
"6 4\n4 8 15 16 23 42\n1000 1000 1000 1000\n"
] | [
"3\n",
"0\n",
"4\n"
] | The first example is described in the problem statement.
In the second example Maxim cannot buy any game because the value of the first bill in his wallet is smaller than the cost of any game in the shop.
In the third example the values of the bills in Maxim's wallet are large enough to buy any game he encounter until he runs out of bills in his wallet. | [
{
"input": "5 4\n2 4 5 2 4\n5 3 4 6",
"output": "3"
},
{
"input": "5 2\n20 40 50 20 40\n19 20",
"output": "0"
},
{
"input": "6 4\n4 8 15 16 23 42\n1000 1000 1000 1000",
"output": "4"
},
{
"input": "5 1\n1 1 1 1 1\n5",
"output": "1"
},
{
"input": "5 1\n10 1 1 1 1\n... | 155 | 0 | 3 | 871 | |
667 | Coat of Anticubism | [
"constructive algorithms",
"geometry"
] | null | null | As some of you know, cubism is a trend in art, where the problem of constructing volumetrical shape on a plane with a combination of three-dimensional geometric shapes comes to the fore.
A famous sculptor Cicasso, whose self-portrait you can contemplate, hates cubism. He is more impressed by the idea to transmit two-dimensional objects through three-dimensional objects by using his magnificent sculptures. And his new project is connected with this. Cicasso wants to make a coat for the haters of anticubism. To do this, he wants to create a sculpture depicting a well-known geometric primitive — convex polygon.
Cicasso prepared for this a few blanks, which are rods with integer lengths, and now he wants to bring them together. The *i*-th rod is a segment of length *l**i*.
The sculptor plans to make a convex polygon with a nonzero area, using all rods he has as its sides. Each rod should be used as a side to its full length. It is forbidden to cut, break or bend rods. However, two sides may form a straight angle .
Cicasso knows that it is impossible to make a convex polygon with a nonzero area out of the rods with the lengths which he had chosen. Cicasso does not want to leave the unused rods, so the sculptor decides to make another rod-blank with an integer length so that his problem is solvable. Of course, he wants to make it as short as possible, because the materials are expensive, and it is improper deed to spend money for nothing.
Help sculptor! | The first line contains an integer *n* (3<=≤<=*n*<=≤<=105) — a number of rod-blanks.
The second line contains *n* integers *l**i* (1<=≤<=*l**i*<=≤<=109) — lengths of rods, which Cicasso already has. It is guaranteed that it is impossible to make a polygon with *n* vertices and nonzero area using the rods Cicasso already has. | Print the only integer *z* — the minimum length of the rod, so that after adding it it can be possible to construct convex polygon with (*n*<=+<=1) vertices and nonzero area from all of the rods. | [
"3\n1 2 1\n",
"5\n20 4 3 2 1\n"
] | [
"1\n",
"11\n"
] | In the first example triangle with sides {1 + 1 = 2, 2, 1} can be formed from a set of lengths {1, 1, 1, 2}.
In the second example you can make a triangle with lengths {20, 11, 4 + 3 + 2 + 1 = 10}. | [
{
"input": "3\n1 2 1",
"output": "1"
},
{
"input": "5\n20 4 3 2 1",
"output": "11"
},
{
"input": "7\n77486105 317474713 89523018 332007362 7897847 949616701 54820086",
"output": "70407571"
},
{
"input": "14\n245638694 2941428 4673577 12468 991349408 44735727 14046308 60637707... | 46 | 5,120,000 | 0 | 873 | |
232 | Cycles | [
"binary search",
"constructive algorithms",
"graphs",
"greedy"
] | null | null | John Doe started thinking about graphs. After some thought he decided that he wants to paint an undirected graph, containing exactly *k* cycles of length 3.
A cycle of length 3 is an unordered group of three distinct graph vertices *a*, *b* and *c*, such that each pair of them is connected by a graph edge.
John has been painting for long, but he has not been a success. Help him find such graph. Note that the number of vertices there shouldn't exceed 100, or else John will have problems painting it. | A single line contains an integer *k* (1<=≤<=*k*<=≤<=105) — the number of cycles of length 3 in the required graph. | In the first line print integer *n* (3<=≤<=*n*<=≤<=100) — the number of vertices in the found graph. In each of next *n* lines print *n* characters "0" and "1": the *i*-th character of the *j*-th line should equal "0", if vertices *i* and *j* do not have an edge between them, otherwise it should equal "1". Note that as the required graph is undirected, the *i*-th character of the *j*-th line must equal the *j*-th character of the *i*-th line. The graph shouldn't contain self-loops, so the *i*-th character of the *i*-th line must equal "0" for all *i*. | [
"1\n",
"10\n"
] | [
"3\n011\n101\n110\n",
"5\n01111\n10111\n11011\n11101\n11110\n"
] | none | [
{
"input": "1",
"output": "3\n011\n101\n110"
},
{
"input": "10",
"output": "5\n01111\n10111\n11011\n11101\n11110"
},
{
"input": "2",
"output": "4\n0111\n1011\n1100\n1100"
},
{
"input": "3",
"output": "5\n01001\n10111\n01001\n01001\n11110"
},
{
"input": "4",
"o... | 156 | 102,400 | 3 | 874 | |
342 | Xenia and Divisors | [
"greedy",
"implementation"
] | null | null | Xenia the mathematician has a sequence consisting of *n* (*n* is divisible by 3) positive integers, each of them is at most 7. She wants to split the sequence into groups of three so that for each group of three *a*,<=*b*,<=*c* the following conditions held:
- *a*<=<<=*b*<=<<=*c*; - *a* divides *b*, *b* divides *c*.
Naturally, Xenia wants each element of the sequence to belong to exactly one group of three. Thus, if the required partition exists, then it has groups of three.
Help Xenia, find the required partition or else say that it doesn't exist. | The first line contains integer *n* (3<=≤<=*n*<=≤<=99999) — the number of elements in the sequence. The next line contains *n* positive integers, each of them is at most 7.
It is guaranteed that *n* is divisible by 3. | If the required partition exists, print groups of three. Print each group as values of the elements it contains. You should print values in increasing order. Separate the groups and integers in groups by whitespaces. If there are multiple solutions, you can print any of them.
If there is no solution, print -1. | [
"6\n1 1 1 2 2 2\n",
"6\n2 2 1 1 4 6\n"
] | [
"-1\n",
"1 2 4\n1 2 6\n"
] | none | [
{
"input": "6\n1 1 1 2 2 2",
"output": "-1"
},
{
"input": "6\n2 2 1 1 4 6",
"output": "1 2 4\n1 2 6"
},
{
"input": "3\n1 2 3",
"output": "-1"
},
{
"input": "3\n7 5 7",
"output": "-1"
},
{
"input": "3\n1 3 4",
"output": "-1"
},
{
"input": "3\n1 1 1",
... | 46 | 0 | 0 | 875 | |
559 | Gerald's Hexagon | [
"brute force",
"geometry",
"math"
] | null | null | Gerald got a very curious hexagon for his birthday. The boy found out that all the angles of the hexagon are equal to . Then he measured the length of its sides, and found that each of them is equal to an integer number of centimeters. There the properties of the hexagon ended and Gerald decided to draw on it.
He painted a few lines, parallel to the sides of the hexagon. The lines split the hexagon into regular triangles with sides of 1 centimeter. Now Gerald wonders how many triangles he has got. But there were so many of them that Gerald lost the track of his counting. Help the boy count the triangles. | The first and the single line of the input contains 6 space-separated integers *a*1,<=*a*2,<=*a*3,<=*a*4,<=*a*5 and *a*6 (1<=≤<=*a**i*<=≤<=1000) — the lengths of the sides of the hexagons in centimeters in the clockwise order. It is guaranteed that the hexagon with the indicated properties and the exactly such sides exists. | Print a single integer — the number of triangles with the sides of one 1 centimeter, into which the hexagon is split. | [
"1 1 1 1 1 1\n",
"1 2 1 2 1 2\n"
] | [
"6\n",
"13\n"
] | This is what Gerald's hexagon looks like in the first sample:
<img class="tex-graphics" src="https://espresso.codeforces.com/84d193e27b02c38eb1eadc536602a2ec0b9f9519.png" style="max-width: 100.0%;max-height: 100.0%;"/>
And that's what it looks like in the second sample:
<img class="tex-graphics" src="https://espresso.codeforces.com/e29076a96da8ca864654cc6195654d9bf07d31ce.png" style="max-width: 100.0%;max-height: 100.0%;"/> | [
{
"input": "1 1 1 1 1 1",
"output": "6"
},
{
"input": "1 2 1 2 1 2",
"output": "13"
},
{
"input": "2 4 5 3 3 6",
"output": "83"
},
{
"input": "45 19 48 18 46 21",
"output": "6099"
},
{
"input": "66 6 65 6 66 5",
"output": "5832"
},
{
"input": "7 5 4 8 ... | 155 | 0 | 3 | 876 | |
719 | Anatoly and Cockroaches | [
"greedy"
] | null | null | Anatoly lives in the university dorm as many other students do. As you know, cockroaches are also living there together with students. Cockroaches might be of two colors: black and red. There are *n* cockroaches living in Anatoly's room.
Anatoly just made all his cockroaches to form a single line. As he is a perfectionist, he would like the colors of cockroaches in the line to alternate. He has a can of black paint and a can of red paint. In one turn he can either swap any two cockroaches, or take any single cockroach and change it's color.
Help Anatoly find out the minimum number of turns he needs to make the colors of cockroaches in the line alternate. | The first line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=100<=000) — the number of cockroaches.
The second line contains a string of length *n*, consisting of characters 'b' and 'r' that denote black cockroach and red cockroach respectively. | Print one integer — the minimum number of moves Anatoly has to perform in order to make the colors of cockroaches in the line to alternate. | [
"5\nrbbrr\n",
"5\nbbbbb\n",
"3\nrbr\n"
] | [
"1\n",
"2\n",
"0\n"
] | In the first sample, Anatoly has to swap third and fourth cockroaches. He needs 1 turn to do this.
In the second sample, the optimum answer is to paint the second and the fourth cockroaches red. This requires 2 turns.
In the third sample, the colors of cockroaches in the line are alternating already, thus the answer is 0. | [
{
"input": "5\nrbbrr",
"output": "1"
},
{
"input": "5\nbbbbb",
"output": "2"
},
{
"input": "3\nrbr",
"output": "0"
},
{
"input": "13\nrbbbrbrrbrrbb",
"output": "3"
},
{
"input": "18\nrrrrrrrrrrrrrrrrrb",
"output": "8"
},
{
"input": "100\nbrbbbrrrbbrbrb... | 124 | 409,600 | 3 | 877 | |
275 | Lights Out | [
"implementation"
] | null | null | Lenny is playing a game on a 3<=×<=3 grid of lights. In the beginning of the game all lights are switched on. Pressing any of the lights will toggle it and all side-adjacent lights. The goal of the game is to switch all the lights off. We consider the toggling as follows: if the light was switched on then it will be switched off, if it was switched off then it will be switched on.
Lenny has spent some time playing with the grid and by now he has pressed each light a certain number of times. Given the number of times each light is pressed, you have to print the current state of each light. | The input consists of three rows. Each row contains three integers each between 0 to 100 inclusive. The *j*-th number in the *i*-th row is the number of times the *j*-th light of the *i*-th row of the grid is pressed. | Print three lines, each containing three characters. The *j*-th character of the *i*-th line is "1" if and only if the corresponding light is switched on, otherwise it's "0". | [
"1 0 0\n0 0 0\n0 0 1\n",
"1 0 1\n8 8 8\n2 0 3\n"
] | [
"001\n010\n100\n",
"010\n011\n100\n"
] | none | [
{
"input": "1 0 0\n0 0 0\n0 0 1",
"output": "001\n010\n100"
},
{
"input": "1 0 1\n8 8 8\n2 0 3",
"output": "010\n011\n100"
},
{
"input": "13 85 77\n25 50 45\n65 79 9",
"output": "000\n010\n000"
},
{
"input": "96 95 5\n8 84 74\n67 31 61",
"output": "011\n011\n101"
},
{... | 62 | 6,963,200 | 3 | 879 | |
754 | Ilya and tic-tac-toe game | [
"brute force",
"implementation"
] | null | null | Ilya is an experienced player in tic-tac-toe on the 4<=×<=4 field. He always starts and plays with Xs. He played a lot of games today with his friend Arseny. The friends became tired and didn't finish the last game. It was Ilya's turn in the game when they left it. Determine whether Ilya could have won the game by making single turn or not.
The rules of tic-tac-toe on the 4<=×<=4 field are as follows. Before the first turn all the field cells are empty. The two players take turns placing their signs into empty cells (the first player places Xs, the second player places Os). The player who places Xs goes first, the another one goes second. The winner is the player who first gets three of his signs in a row next to each other (horizontal, vertical or diagonal). | The tic-tac-toe position is given in four lines.
Each of these lines contains four characters. Each character is '.' (empty cell), 'x' (lowercase English letter x), or 'o' (lowercase English letter o). It is guaranteed that the position is reachable playing tic-tac-toe, and it is Ilya's turn now (in particular, it means that the game is not finished). It is possible that all the cells are empty, it means that the friends left without making single turn. | Print single line: "YES" in case Ilya could have won by making single turn, and "NO" otherwise. | [
"xx..\n.oo.\nx...\noox.\n",
"x.ox\nox..\nx.o.\noo.x\n",
"x..x\n..oo\no...\nx.xo\n",
"o.x.\no...\n.x..\nooxx\n"
] | [
"YES\n",
"NO\n",
"YES\n",
"NO\n"
] | In the first example Ilya had two winning moves: to the empty cell in the left column and to the leftmost empty cell in the first row.
In the second example it wasn't possible to win by making single turn.
In the third example Ilya could have won by placing X in the last row between two existing Xs.
In the fourth example it wasn't possible to win by making single turn. | [
{
"input": "xx..\n.oo.\nx...\noox.",
"output": "YES"
},
{
"input": "x.ox\nox..\nx.o.\noo.x",
"output": "NO"
},
{
"input": "x..x\n..oo\no...\nx.xo",
"output": "YES"
},
{
"input": "o.x.\no...\n.x..\nooxx",
"output": "NO"
},
{
"input": ".xox\no.x.\nx.o.\n..o.",
"... | 93 | 4,915,200 | 0 | 881 | |
967 | Watering System | [
"math",
"sortings"
] | null | null | Arkady wants to water his only flower. Unfortunately, he has a very poor watering system that was designed for $n$ flowers and so it looks like a pipe with $n$ holes. Arkady can only use the water that flows from the first hole.
Arkady can block some of the holes, and then pour $A$ liters of water into the pipe. After that, the water will flow out from the non-blocked holes proportionally to their sizes $s_1, s_2, \ldots, s_n$. In other words, if the sum of sizes of non-blocked holes is $S$, and the $i$-th hole is not blocked, $\frac{s_i \cdot A}{S}$ liters of water will flow out of it.
What is the minimum number of holes Arkady should block to make at least $B$ liters of water flow out of the first hole? | The first line contains three integers $n$, $A$, $B$ ($1 \le n \le 100\,000$, $1 \le B \le A \le 10^4$) — the number of holes, the volume of water Arkady will pour into the system, and the volume he wants to get out of the first hole.
The second line contains $n$ integers $s_1, s_2, \ldots, s_n$ ($1 \le s_i \le 10^4$) — the sizes of the holes. | Print a single integer — the number of holes Arkady should block. | [
"4 10 3\n2 2 2 2\n",
"4 80 20\n3 2 1 4\n",
"5 10 10\n1000 1 1 1 1\n"
] | [
"1\n",
"0\n",
"4\n"
] | In the first example Arkady should block at least one hole. After that, $\frac{10 \cdot 2}{6} \approx 3.333$ liters of water will flow out of the first hole, and that suits Arkady.
In the second example even without blocking any hole, $\frac{80 \cdot 3}{10} = 24$ liters will flow out of the first hole, that is not less than $20$.
In the third example Arkady has to block all holes except the first to make all water flow out of the first hole. | [
{
"input": "4 10 3\n2 2 2 2",
"output": "1"
},
{
"input": "4 80 20\n3 2 1 4",
"output": "0"
},
{
"input": "5 10 10\n1000 1 1 1 1",
"output": "4"
},
{
"input": "10 300 100\n20 1 3 10 8 5 3 6 4 3",
"output": "1"
},
{
"input": "10 300 100\n20 25 68 40 60 37 44 85 23 ... | 1,000 | 12,288,000 | 0 | 888 | |
55 | Smallest number | [
"brute force"
] | B. Smallest number | 2 | 256 | Recently, Vladimir got bad mark in algebra again. To avoid such unpleasant events in future he decided to train his arithmetic skills. He wrote four integer numbers *a*, *b*, *c*, *d* on the blackboard. During each of the next three minutes he took two numbers from the blackboard (not necessarily adjacent) and replaced them with their sum or their product. In the end he got one number. Unfortunately, due to the awful memory he forgot that number, but he remembers four original numbers, sequence of the operations and his surprise because of the very small result. Help Vladimir remember the forgotten number: find the smallest number that can be obtained from the original numbers by the given sequence of operations. | First line contains four integers separated by space: 0<=≤<=*a*,<=*b*,<=*c*,<=*d*<=≤<=1000 — the original numbers. Second line contains three signs ('+' or '*' each) separated by space — the sequence of the operations in the order of performing. ('+' stands for addition, '*' — multiplication) | Output one integer number — the minimal result which can be obtained.
Please, do not use %lld specificator to read or write 64-bit integers in C++. It is preffered to use cin (also you may use %I64d). | [
"1 1 1 1\n+ + *\n",
"2 2 2 2\n* * +\n",
"1 2 3 4\n* + +\n"
] | [
"3\n",
"8\n",
"9\n"
] | none | [
{
"input": "1 1 1 1\n+ + *",
"output": "3"
},
{
"input": "2 2 2 2\n* * +",
"output": "8"
},
{
"input": "1 2 3 4\n* + +",
"output": "9"
},
{
"input": "15 1 3 1\n* * +",
"output": "18"
},
{
"input": "8 1 7 14\n+ + +",
"output": "30"
},
{
"input": "7 17 3... | 92 | 102,400 | 0 | 892 |
368 | Sereja and Suffixes | [
"data structures",
"dp"
] | null | null | Sereja has an array *a*, consisting of *n* integers *a*1, *a*2, ..., *a**n*. The boy cannot sit and do nothing, he decided to study an array. Sereja took a piece of paper and wrote out *m* integers *l*1,<=*l*2,<=...,<=*l**m* (1<=≤<=*l**i*<=≤<=*n*). For each number *l**i* he wants to know how many distinct numbers are staying on the positions *l**i*, *l**i*<=+<=1, ..., *n*. Formally, he want to find the number of distinct numbers among *a**l**i*,<=*a**l**i*<=+<=1,<=...,<=*a**n*.?
Sereja wrote out the necessary array elements but the array was so large and the boy was so pressed for time. Help him, find the answer for the described question for each *l**i*. | The first line contains two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=105). The second line contains *n* integers *a*1, *a*2, ..., *a**n* (1<=≤<=*a**i*<=≤<=105) — the array elements.
Next *m* lines contain integers *l*1,<=*l*2,<=...,<=*l**m*. The *i*-th line contains integer *l**i* (1<=≤<=*l**i*<=≤<=*n*). | Print *m* lines — on the *i*-th line print the answer to the number *l**i*. | [
"10 10\n1 2 3 4 1 2 3 4 100000 99999\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10\n"
] | [
"6\n6\n6\n6\n6\n5\n4\n3\n2\n1\n"
] | none | [
{
"input": "10 10\n1 2 3 4 1 2 3 4 100000 99999\n1\n2\n3\n4\n5\n6\n7\n8\n9\n10",
"output": "6\n6\n6\n6\n6\n5\n4\n3\n2\n1"
},
{
"input": "8 3\n8 6 4 3 4 2 4 8\n6\n4\n2",
"output": "3\n4\n5"
},
{
"input": "7 10\n1 3 8 6 2 2 7\n4\n2\n6\n3\n4\n4\n6\n2\n7\n4",
"output": "3\n5\n2\n4\n3\n3\... | 1,000 | 5,222,400 | 0 | 893 | |
250 | Restoring IPv6 | [
"implementation",
"strings"
] | null | null | An IPv6-address is a 128-bit number. For convenience, this number is recorded in blocks of 16 bits in hexadecimal record, the blocks are separated by colons — 8 blocks in total, each block has four hexadecimal digits. Here is an example of the correct record of a IPv6 address: "0124:5678:90ab:cdef:0124:5678:90ab:cdef". We'll call such format of recording an IPv6-address full.
Besides the full record of an IPv6 address there is a short record format. The record of an IPv6 address can be shortened by removing one or more leading zeroes at the beginning of each block. However, each block should contain at least one digit in the short format. For example, the leading zeroes can be removed like that: "a56f:00d3:0000:0124:0001:f19a:1000:0000" <=→<= "a56f:d3:0:0124:01:f19a:1000:00". There are more ways to shorten zeroes in this IPv6 address.
Some IPv6 addresses contain long sequences of zeroes. Continuous sequences of 16-bit zero blocks can be shortened to "::". A sequence can consist of one or several consecutive blocks, with all 16 bits equal to 0.
You can see examples of zero block shortenings below:
- "a56f:00d3:0000:0124:0001:0000:0000:0000" <=→<= "a56f:00d3:0000:0124:0001::"; - "a56f:0000:0000:0124:0001:0000:1234:0ff0" <=→<= "a56f::0124:0001:0000:1234:0ff0"; - "a56f:0000:0000:0000:0001:0000:1234:0ff0" <=→<= "a56f:0000::0000:0001:0000:1234:0ff0"; - "a56f:00d3:0000:0124:0001:0000:0000:0000" <=→<= "a56f:00d3:0000:0124:0001::0000"; - "0000:0000:0000:0000:0000:0000:0000:0000" <=→<= "::".
It is not allowed to shorten zero blocks in the address more than once. This means that the short record can't contain the sequence of characters "::" more than once. Otherwise, it will sometimes be impossible to determine the number of zero blocks, each represented by a double colon.
The format of the record of the IPv6 address after removing the leading zeroes and shortening the zero blocks is called short.
You've got several short records of IPv6 addresses. Restore their full record. | The first line contains a single integer *n* — the number of records to restore (1<=≤<=*n*<=≤<=100).
Each of the following *n* lines contains a string — the short IPv6 addresses. Each string only consists of string characters "0123456789abcdef:".
It is guaranteed that each short address is obtained by the way that is described in the statement from some full IPv6 address. | For each short IPv6 address from the input print its full record on a separate line. Print the full records for the short IPv6 addresses in the order, in which the short records follow in the input. | [
"6\na56f:d3:0:0124:01:f19a:1000:00\na56f:00d3:0000:0124:0001::\na56f::0124:0001:0000:1234:0ff0\na56f:0000::0000:0001:0000:1234:0ff0\n::\n0ea::4d:f4:6:0\n"
] | [
"a56f:00d3:0000:0124:0001:f19a:1000:0000\na56f:00d3:0000:0124:0001:0000:0000:0000\na56f:0000:0000:0124:0001:0000:1234:0ff0\na56f:0000:0000:0000:0001:0000:1234:0ff0\n0000:0000:0000:0000:0000:0000:0000:0000\n00ea:0000:0000:0000:004d:00f4:0006:0000\n"
] | none | [
{
"input": "6\na56f:d3:0:0124:01:f19a:1000:00\na56f:00d3:0000:0124:0001::\na56f::0124:0001:0000:1234:0ff0\na56f:0000::0000:0001:0000:1234:0ff0\n::\n0ea::4d:f4:6:0",
"output": "a56f:00d3:0000:0124:0001:f19a:1000:0000\na56f:00d3:0000:0124:0001:0000:0000:0000\na56f:0000:0000:0124:0001:0000:1234:0ff0\na56f:0000... | 30 | 0 | -1 | 894 | |
727 | Transformation: from A to B | [
"brute force",
"dfs and similar",
"math"
] | null | null | Vasily has a number *a*, which he wants to turn into a number *b*. For this purpose, he can do two types of operations:
- multiply the current number by 2 (that is, replace the number *x* by 2·*x*); - append the digit 1 to the right of current number (that is, replace the number *x* by 10·*x*<=+<=1).
You need to help Vasily to transform the number *a* into the number *b* using only the operations described above, or find that it is impossible.
Note that in this task you are not required to minimize the number of operations. It suffices to find any way to transform *a* into *b*. | The first line contains two positive integers *a* and *b* (1<=≤<=*a*<=<<=*b*<=≤<=109) — the number which Vasily has and the number he wants to have. | If there is no way to get *b* from *a*, print "NO" (without quotes).
Otherwise print three lines. On the first line print "YES" (without quotes). The second line should contain single integer *k* — the length of the transformation sequence. On the third line print the sequence of transformations *x*1,<=*x*2,<=...,<=*x**k*, where:
- *x*1 should be equal to *a*, - *x**k* should be equal to *b*, - *x**i* should be obtained from *x**i*<=-<=1 using any of two described operations (1<=<<=*i*<=≤<=*k*).
If there are multiple answers, print any of them. | [
"2 162\n",
"4 42\n",
"100 40021\n"
] | [
"YES\n5\n2 4 8 81 162 \n",
"NO\n",
"YES\n5\n100 200 2001 4002 40021 \n"
] | none | [
{
"input": "2 162",
"output": "YES\n5\n2 4 8 81 162 "
},
{
"input": "4 42",
"output": "NO"
},
{
"input": "100 40021",
"output": "YES\n5\n100 200 2001 4002 40021 "
},
{
"input": "1 111111111",
"output": "YES\n9\n1 11 111 1111 11111 111111 1111111 11111111 111111111 "
},
... | 186 | 9,318,400 | 3 | 896 | |
492 | Vanya and Cubes | [
"implementation"
] | null | null | Vanya got *n* cubes. He decided to build a pyramid from them. Vanya wants to build the pyramid as follows: the top level of the pyramid must consist of 1 cube, the second level must consist of 1<=+<=2<==<=3 cubes, the third level must have 1<=+<=2<=+<=3<==<=6 cubes, and so on. Thus, the *i*-th level of the pyramid must have 1<=+<=2<=+<=...<=+<=(*i*<=-<=1)<=+<=*i* cubes.
Vanya wants to know what is the maximum height of the pyramid that he can make using the given cubes. | The first line contains integer *n* (1<=≤<=*n*<=≤<=104) — the number of cubes given to Vanya. | Print the maximum possible height of the pyramid in the single line. | [
"1\n",
"25\n"
] | [
"1\n",
"4\n"
] | Illustration to the second sample: | [
{
"input": "1",
"output": "1"
},
{
"input": "25",
"output": "4"
},
{
"input": "2",
"output": "1"
},
{
"input": "4115",
"output": "28"
},
{
"input": "9894",
"output": "38"
},
{
"input": "7969",
"output": "35"
},
{
"input": "6560",
"outpu... | 46 | 0 | 3 | 899 | |
755 | PolandBall and Game | [
"binary search",
"data structures",
"games",
"greedy",
"sortings",
"strings"
] | null | null | PolandBall is playing a game with EnemyBall. The rules are simple. Players have to say words in turns. You cannot say a word which was already said. PolandBall starts. The Ball which can't say a new word loses.
You're given two lists of words familiar to PolandBall and EnemyBall. Can you determine who wins the game, if both play optimally? | The first input line contains two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=103) — number of words PolandBall and EnemyBall know, respectively.
Then *n* strings follow, one per line — words familiar to PolandBall.
Then *m* strings follow, one per line — words familiar to EnemyBall.
Note that one Ball cannot know a word more than once (strings are unique), but some words can be known by both players.
Each word is non-empty and consists of no more than 500 lowercase English alphabet letters. | In a single line of print the answer — "YES" if PolandBall wins and "NO" otherwise. Both Balls play optimally. | [
"5 1\npolandball\nis\na\ncool\ncharacter\nnope\n",
"2 2\nkremowka\nwadowicka\nkremowka\nwiedenska\n",
"1 2\na\na\nb\n"
] | [
"YES",
"YES",
"NO"
] | In the first example PolandBall knows much more words and wins effortlessly.
In the second example if PolandBall says kremowka first, then EnemyBall cannot use that word anymore. EnemyBall can only say wiedenska. PolandBall says wadowicka and wins. | [
{
"input": "5 1\npolandball\nis\na\ncool\ncharacter\nnope",
"output": "YES"
},
{
"input": "2 2\nkremowka\nwadowicka\nkremowka\nwiedenska",
"output": "YES"
},
{
"input": "1 2\na\na\nb",
"output": "NO"
},
{
"input": "2 2\na\nb\nb\nc",
"output": "YES"
},
{
"input": "... | 187 | 5,120,000 | 3 | 901 | |
784 | INTERCALC | [
"*special",
"implementation"
] | null | null | DO YOU EXPECT ME TO FIND THIS OUT?
WHAT BASE AND/XOR LANGUAGE INCLUDES string?
DON'T BYTE OF MORE THAN YOU CAN CHEW
YOU CAN ONLY DISTORT THE LARGEST OF MATHEMATICS SO FAR
SAYING "ABRACADABRA" WITHOUT A MAGIC AND WON'T DO YOU ANY GOOD
THE LAST STACK RUPTURES. ALL DIE. OH, THE EMBARRASSMENT!
I HAVE NO ARRAY AND I MUST SCREAM
ELEMENTS MAY NOT BE STORED IN WEST HYPERSPACE | The first line of input data contains a single integer *n* (1<=≤<=*n*<=≤<=10).
The second line of input data contains *n* space-separated integers *a**i* (1<=≤<=*a**i*<=≤<=11). | Output a single integer. | [
"4\n2 5 3 1\n"
] | [
"4\n"
] | none | [
{
"input": "4\n2 5 3 1",
"output": "4"
},
{
"input": "2\n1 5",
"output": "0"
},
{
"input": "1\n8",
"output": "0"
},
{
"input": "6\n1 1 1 3 2 9",
"output": "0"
},
{
"input": "5\n8 9 3 1 9",
"output": "0"
},
{
"input": "6\n1 5 2 1 7 11",
"output": "0... | 46 | 4,608,000 | -1 | 906 | |
572 | Order Book | [
"data structures",
"greedy",
"implementation",
"sortings"
] | null | null | In this task you need to process a set of stock exchange orders and use them to create order book.
An order is an instruction of some participant to buy or sell stocks on stock exchange. The order number *i* has price *p**i*, direction *d**i* — buy or sell, and integer *q**i*. This means that the participant is ready to buy or sell *q**i* stocks at price *p**i* for one stock. A value *q**i* is also known as a volume of an order.
All orders with the same price *p* and direction *d* are merged into one aggregated order with price *p* and direction *d*. The volume of such order is a sum of volumes of the initial orders.
An order book is a list of aggregated orders, the first part of which contains sell orders sorted by price in descending order, the second contains buy orders also sorted by price in descending order.
An order book of depth *s* contains *s* best aggregated orders for each direction. A buy order is better if it has higher price and a sell order is better if it has lower price. If there are less than *s* aggregated orders for some direction then all of them will be in the final order book.
You are given *n* stock exhange orders. Your task is to print order book of depth *s* for these orders. | The input starts with two positive integers *n* and *s* (1<=≤<=*n*<=≤<=1000,<=1<=≤<=*s*<=≤<=50), the number of orders and the book depth.
Next *n* lines contains a letter *d**i* (either 'B' or 'S'), an integer *p**i* (0<=≤<=*p**i*<=≤<=105) and an integer *q**i* (1<=≤<=*q**i*<=≤<=104) — direction, price and volume respectively. The letter 'B' means buy, 'S' means sell. The price of any sell order is higher than the price of any buy order. | Print no more than 2*s* lines with aggregated orders from order book of depth *s*. The output format for orders should be the same as in input. | [
"6 2\nB 10 3\nS 50 2\nS 40 1\nS 50 6\nB 20 4\nB 25 10\n"
] | [
"S 50 8\nS 40 1\nB 25 10\nB 20 4\n"
] | Denote (x, y) an order with price *x* and volume *y*. There are 3 aggregated buy orders (10, 3), (20, 4), (25, 10) and two sell orders (50, 8), (40, 1) in the sample.
You need to print no more than two best orders for each direction, so you shouldn't print the order (10 3) having the worst price among buy orders. | [
{
"input": "6 2\nB 10 3\nS 50 2\nS 40 1\nS 50 6\nB 20 4\nB 25 10",
"output": "S 50 8\nS 40 1\nB 25 10\nB 20 4"
},
{
"input": "2 1\nB 7523 5589\nS 69799 1711",
"output": "S 69799 1711\nB 7523 5589"
},
{
"input": "1 1\nB 48259 991",
"output": "B 48259 991"
},
{
"input": "1 50\n... | 62 | 0 | 0 | 907 | |
844 | Diversity | [
"greedy",
"implementation",
"strings"
] | null | null | Calculate the minimum number of characters you need to change in the string *s*, so that it contains at least *k* different letters, or print that it is impossible.
String *s* consists only of lowercase Latin letters, and it is allowed to change characters only to lowercase Latin letters too. | First line of input contains string *s*, consisting only of lowercase Latin letters (1<=≤<=|*s*|<=≤<=1000, |*s*| denotes the length of *s*).
Second line of input contains integer *k* (1<=≤<=*k*<=≤<=26). | Print single line with a minimum number of necessary changes, or the word «impossible» (without quotes) if it is impossible. | [
"yandex\n6\n",
"yahoo\n5\n",
"google\n7\n"
] | [
"0\n",
"1\n",
"impossible\n"
] | In the first test case string contains 6 different letters, so we don't need to change anything.
In the second test case string contains 4 different letters: {'*a*', '*h*', '*o*', '*y*'}. To get 5 different letters it is necessary to change one occurrence of '*o*' to some letter, which doesn't occur in the string, for example, {'*b*'}.
In the third test case, it is impossible to make 7 different letters because the length of the string is 6. | [
{
"input": "yandex\n6",
"output": "0"
},
{
"input": "yahoo\n5",
"output": "1"
},
{
"input": "google\n7",
"output": "impossible"
},
{
"input": "a\n1",
"output": "0"
},
{
"input": "z\n2",
"output": "impossible"
},
{
"input": "fwgfrwgkuwghfiruhewgirueguhe... | 62 | 0 | 0 | 911 | |
670 | Holidays | [
"brute force",
"constructive algorithms",
"greedy",
"math"
] | null | null | On the planet Mars a year lasts exactly *n* days (there are no leap years on Mars). But Martians have the same weeks as earthlings — 5 work days and then 2 days off. Your task is to determine the minimum possible and the maximum possible number of days off per year on Mars. | The first line of the input contains a positive integer *n* (1<=≤<=*n*<=≤<=1<=000<=000) — the number of days in a year on Mars. | Print two integers — the minimum possible and the maximum possible number of days off per year on Mars. | [
"14\n",
"2\n"
] | [
"4 4\n",
"0 2\n"
] | In the first sample there are 14 days in a year on Mars, and therefore independently of the day a year starts with there will be exactly 4 days off .
In the second sample there are only 2 days in a year on Mars, and they can both be either work days or days off. | [
{
"input": "14",
"output": "4 4"
},
{
"input": "2",
"output": "0 2"
},
{
"input": "1",
"output": "0 1"
},
{
"input": "3",
"output": "0 2"
},
{
"input": "4",
"output": "0 2"
},
{
"input": "5",
"output": "0 2"
},
{
"input": "6",
"output":... | 46 | 0 | 0 | 914 | |
614 | Gena's Code | [
"implementation",
"math"
] | null | null | It's the year 4527 and the tanks game that we all know and love still exists. There also exists Great Gena's code, written in 2016. The problem this code solves is: given the number of tanks that go into the battle from each country, find their product. If it is turns to be too large, then the servers might have not enough time to assign tanks into teams and the whole game will collapse!
There are exactly *n* distinct countries in the world and the *i*-th country added *a**i* tanks to the game. As the developers of the game are perfectionists, the number of tanks from each country is beautiful. A beautiful number, according to the developers, is such number that its decimal representation consists only of digits '1' and '0', moreover it contains at most one digit '1'. However, due to complaints from players, some number of tanks of one country was removed from the game, hence the number of tanks of this country may not remain beautiful.
Your task is to write the program that solves exactly the same problem in order to verify Gena's code correctness. Just in case. | The first line of the input contains the number of countries *n* (1<=≤<=*n*<=≤<=100<=000). The second line contains *n* non-negative integers *a**i* without leading zeroes — the number of tanks of the *i*-th country.
It is guaranteed that the second line contains at least *n*<=-<=1 beautiful numbers and the total length of all these number's representations doesn't exceed 100<=000. | Print a single number without leading zeroes — the product of the number of tanks presented by each country. | [
"3\n5 10 1\n",
"4\n1 1 10 11\n",
"5\n0 3 1 100 1\n"
] | [
"50",
"110",
"0"
] | In sample 1 numbers 10 and 1 are beautiful, number 5 is not not.
In sample 2 number 11 is not beautiful (contains two '1's), all others are beautiful.
In sample 3 number 3 is not beautiful, all others are beautiful. | [
{
"input": "3\n5 10 1",
"output": "50"
},
{
"input": "4\n1 1 10 11",
"output": "110"
},
{
"input": "5\n0 3 1 100 1",
"output": "0"
},
{
"input": "40\n10 100 10 1 10 10 100 10 10 100 10 100 100 10 1824868942 100 100 1 10 100 100 10 100 100 10 100 10 1 10 100 100 100 10 1 10 1 ... | 202 | 1,843,200 | 3 | 915 | |
900 | Find Extra One | [
"geometry",
"implementation"
] | null | null | You have *n* distinct points on a plane, none of them lie on *OY* axis. Check that there is a point after removal of which the remaining points are located on one side of the *OY* axis. | The first line contains a single positive integer *n* (2<=≤<=*n*<=≤<=105).
The following *n* lines contain coordinates of the points. The *i*-th of these lines contains two single integers *x**i* and *y**i* (|*x**i*|,<=|*y**i*|<=≤<=109, *x**i*<=≠<=0). No two points coincide. | Print "Yes" if there is such a point, "No" — otherwise.
You can print every letter in any case (upper or lower). | [
"3\n1 1\n-1 -1\n2 -1\n",
"4\n1 1\n2 2\n-1 1\n-2 2\n",
"3\n1 2\n2 1\n4 60\n"
] | [
"Yes",
"No",
"Yes"
] | In the first example the second point can be removed.
In the second example there is no suitable for the condition point.
In the third example any point can be removed. | [
{
"input": "3\n1 1\n-1 -1\n2 -1",
"output": "Yes"
},
{
"input": "4\n1 1\n2 2\n-1 1\n-2 2",
"output": "No"
},
{
"input": "3\n1 2\n2 1\n4 60",
"output": "Yes"
},
{
"input": "10\n1 1\n2 2\n3 3\n4 4\n5 5\n6 6\n7 7\n8 8\n9 9\n-1 -1",
"output": "Yes"
},
{
"input": "2\n1... | 249 | 0 | 0 | 918 | |
7 | Memory Manager | [
"implementation"
] | B. Memory Manager | 1 | 64 | There is little time left before the release of the first national operating system BerlOS. Some of its components are not finished yet — the memory manager is among them. According to the developers' plan, in the first release the memory manager will be very simple and rectilinear. It will support three operations:
- alloc n — to allocate *n* bytes of the memory and return the allocated block's identifier *x*; - erase x — to erase the block with the identifier *x*; - defragment — to defragment the free memory, bringing all the blocks as close to the beginning of the memory as possible and preserving their respective order;
The memory model in this case is very simple. It is a sequence of *m* bytes, numbered for convenience from the first to the *m*-th.
The first operation alloc n takes as the only parameter the size of the memory block that is to be allocated. While processing this operation, a free block of *n* successive bytes is being allocated in the memory. If the amount of such blocks is more than one, the block closest to the beginning of the memory (i.e. to the first byte) is prefered. All these bytes are marked as not free, and the memory manager returns a 32-bit integer numerical token that is the identifier of this block. If it is impossible to allocate a free block of this size, the function returns NULL.
The second operation erase x takes as its parameter the identifier of some block. This operation frees the system memory, marking the bytes of this block as free for further use. In the case when this identifier does not point to the previously allocated block, which has not been erased yet, the function returns ILLEGAL_ERASE_ARGUMENT.
The last operation defragment does not have any arguments and simply brings the occupied memory sections closer to the beginning of the memory without changing their respective order.
In the current implementation you are to use successive integers, starting with 1, as identifiers. Each successful alloc operation procession should return following number. Unsuccessful alloc operations do not affect numeration.
You are to write the implementation of the memory manager. You should output the returned value for each alloc command. You should also output ILLEGAL_ERASE_ARGUMENT for all the failed erase commands. | The first line of the input data contains two positive integers *t* and *m* (1<=≤<=*t*<=≤<=100;1<=≤<=*m*<=≤<=100), where *t* — the amount of operations given to the memory manager for processing, and *m* — the available memory size in bytes. Then there follow *t* lines where the operations themselves are given. The first operation is alloc n (1<=≤<=*n*<=≤<=100), where *n* is an integer. The second one is erase x, where *x* is an arbitrary 32-bit integer numerical token. The third operation is defragment. | Output the sequence of lines. Each line should contain either the result of alloc operation procession , or ILLEGAL_ERASE_ARGUMENT as a result of failed erase operation procession. Output lines should go in the same order in which the operations are processed. Successful procession of alloc operation should return integers, starting with 1, as the identifiers of the allocated blocks. | [
"6 10\nalloc 5\nalloc 3\nerase 1\nalloc 6\ndefragment\nalloc 6\n"
] | [
"1\n2\nNULL\n3\n"
] | none | [
{
"input": "6 10\nalloc 5\nalloc 3\nerase 1\nalloc 6\ndefragment\nalloc 6",
"output": "1\n2\nNULL\n3"
},
{
"input": "6 1\ndefragment\nalloc 10\nalloc 1\nerase -1\nerase 1\nerase 1",
"output": "NULL\n1\nILLEGAL_ERASE_ARGUMENT\nILLEGAL_ERASE_ARGUMENT"
},
{
"input": "14 100\nalloc 99\nalloc... | 186 | 0 | 0 | 922 |
721 | Passwords | [
"implementation",
"math",
"sortings",
"strings"
] | null | null | Vanya is managed to enter his favourite site Codehorses. Vanya uses *n* distinct passwords for sites at all, however he can't remember which one exactly he specified during Codehorses registration.
Vanya will enter passwords in order of non-decreasing their lengths, and he will enter passwords of same length in arbitrary order. Just when Vanya will have entered the correct password, he is immediately authorized on the site. Vanya will not enter any password twice.
Entering any passwords takes one second for Vanya. But if Vanya will enter wrong password *k* times, then he is able to make the next try only 5 seconds after that. Vanya makes each try immediately, that is, at each moment when Vanya is able to enter password, he is doing that.
Determine how many seconds will Vanya need to enter Codehorses in the best case for him (if he spends minimum possible number of second) and in the worst case (if he spends maximum possible amount of seconds). | The first line of the input contains two integers *n* and *k* (1<=≤<=*n*,<=*k*<=≤<=100) — the number of Vanya's passwords and the number of failed tries, after which the access to the site is blocked for 5 seconds.
The next *n* lines contains passwords, one per line — pairwise distinct non-empty strings consisting of latin letters and digits. Each password length does not exceed 100 characters.
The last line of the input contains the Vanya's Codehorses password. It is guaranteed that the Vanya's Codehorses password is equal to some of his *n* passwords. | Print two integers — time (in seconds), Vanya needs to be authorized to Codehorses in the best case for him and in the worst case respectively. | [
"5 2\ncba\nabc\nbb1\nabC\nABC\nabc\n",
"4 100\n11\n22\n1\n2\n22\n"
] | [
"1 15\n",
"3 4\n"
] | Consider the first sample case. As soon as all passwords have the same length, Vanya can enter the right password at the first try as well as at the last try. If he enters it at the first try, he spends exactly 1 second. Thus in the best case the answer is 1. If, at the other hand, he enters it at the last try, he enters another 4 passwords before. He spends 2 seconds to enter first 2 passwords, then he waits 5 seconds as soon as he made 2 wrong tries. Then he spends 2 more seconds to enter 2 wrong passwords, again waits 5 seconds and, finally, enters the correct password spending 1 more second. In summary in the worst case he is able to be authorized in 15 seconds.
Consider the second sample case. There is no way of entering passwords and get the access to the site blocked. As soon as the required password has length of 2, Vanya enters all passwords of length 1 anyway, spending 2 seconds for that. Then, in the best case, he immediately enters the correct password and the answer for the best case is 3, but in the worst case he enters wrong password of length 2 and only then the right one, spending 4 seconds at all. | [
{
"input": "5 2\ncba\nabc\nbb1\nabC\nABC\nabc",
"output": "1 15"
},
{
"input": "4 100\n11\n22\n1\n2\n22",
"output": "3 4"
},
{
"input": "1 1\na1\na1",
"output": "1 1"
},
{
"input": "1 100\na1\na1",
"output": "1 1"
},
{
"input": "2 1\nabc\nAbc\nAbc",
"output": ... | 31 | 0 | 0 | 924 | |
735 | Ostap and Grasshopper | [
"implementation",
"strings"
] | null | null | On the way to Rio de Janeiro Ostap kills time playing with a grasshopper he took with him in a special box. Ostap builds a line of length *n* such that some cells of this line are empty and some contain obstacles. Then, he places his grasshopper to one of the empty cells and a small insect in another empty cell. The grasshopper wants to eat the insect.
Ostap knows that grasshopper is able to jump to any empty cell that is exactly *k* cells away from the current (to the left or to the right). Note that it doesn't matter whether intermediate cells are empty or not as the grasshopper makes a jump over them. For example, if *k*<==<=1 the grasshopper can jump to a neighboring cell only, and if *k*<==<=2 the grasshopper can jump over a single cell.
Your goal is to determine whether there is a sequence of jumps such that grasshopper will get from his initial position to the cell with an insect. | The first line of the input contains two integers *n* and *k* (2<=≤<=*n*<=≤<=100, 1<=≤<=*k*<=≤<=*n*<=-<=1) — the number of cells in the line and the length of one grasshopper's jump.
The second line contains a string of length *n* consisting of characters '.', '#', 'G' and 'T'. Character '.' means that the corresponding cell is empty, character '#' means that the corresponding cell contains an obstacle and grasshopper can't jump there. Character 'G' means that the grasshopper starts at this position and, finally, 'T' means that the target insect is located at this cell. It's guaranteed that characters 'G' and 'T' appear in this line exactly once. | If there exists a sequence of jumps (each jump of length *k*), such that the grasshopper can get from his initial position to the cell with the insect, print "YES" (without quotes) in the only line of the input. Otherwise, print "NO" (without quotes). | [
"5 2\n#G#T#\n",
"6 1\nT....G\n",
"7 3\nT..#..G\n",
"6 2\n..GT..\n"
] | [
"YES\n",
"YES\n",
"NO\n",
"NO\n"
] | In the first sample, the grasshopper can make one jump to the right in order to get from cell 2 to cell 4.
In the second sample, the grasshopper is only able to jump to neighboring cells but the way to the insect is free — he can get there by jumping left 5 times.
In the third sample, the grasshopper can't make a single jump.
In the fourth sample, the grasshopper can only jump to the cells with odd indices, thus he won't be able to reach the insect. | [
{
"input": "5 2\n#G#T#",
"output": "YES"
},
{
"input": "6 1\nT....G",
"output": "YES"
},
{
"input": "7 3\nT..#..G",
"output": "NO"
},
{
"input": "6 2\n..GT..",
"output": "NO"
},
{
"input": "2 1\nGT",
"output": "YES"
},
{
"input": "100 5\nG####.####.###... | 46 | 0 | 3 | 925 | |
34 | Reconnaissance 2 | [
"implementation"
] | A. Reconnaissance 2 | 2 | 256 | *n* soldiers stand in a circle. For each soldier his height *a**i* is known. A reconnaissance unit can be made of such two neighbouring soldiers, whose heights difference is minimal, i.e. |*a**i*<=-<=*a**j*| is minimal. So each of them will be less noticeable with the other. Output any pair of soldiers that can form a reconnaissance unit. | The first line contains integer *n* (2<=≤<=*n*<=≤<=100) — amount of soldiers. Then follow the heights of the soldiers in their order in the circle — *n* space-separated integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=1000). The soldier heights are given in clockwise or counterclockwise direction. | Output two integers — indexes of neighbouring soldiers, who should form a reconnaissance unit. If there are many optimum solutions, output any of them. Remember, that the soldiers stand in a circle. | [
"5\n10 12 13 15 10\n",
"4\n10 20 30 40\n"
] | [
"5 1\n",
"1 2\n"
] | none | [
{
"input": "5\n10 12 13 15 10",
"output": "5 1"
},
{
"input": "4\n10 20 30 40",
"output": "1 2"
},
{
"input": "6\n744 359 230 586 944 442",
"output": "2 3"
},
{
"input": "5\n826 747 849 687 437",
"output": "1 2"
},
{
"input": "5\n999 999 993 969 999",
"output"... | 124 | 6,758,400 | 3.956411 | 928 |
421 | Pasha and Hamsters | [
"constructive algorithms",
"implementation"
] | null | null | Pasha has two hamsters: Arthur and Alexander. Pasha put *n* apples in front of them. Pasha knows which apples Arthur likes. Similarly, Pasha knows which apples Alexander likes. Pasha doesn't want any conflict between the hamsters (as they may like the same apple), so he decided to distribute the apples between the hamsters on his own. He is going to give some apples to Arthur and some apples to Alexander. It doesn't matter how many apples each hamster gets but it is important that each hamster gets only the apples he likes. It is possible that somebody doesn't get any apples.
Help Pasha distribute all the apples between the hamsters. Note that Pasha wants to distribute all the apples, not just some of them. | The first line contains integers *n*, *a*, *b* (1<=≤<=*n*<=≤<=100; 1<=≤<=*a*,<=*b*<=≤<=*n*) — the number of apples Pasha has, the number of apples Arthur likes and the number of apples Alexander likes, correspondingly.
The next line contains *a* distinct integers — the numbers of the apples Arthur likes. The next line contains *b* distinct integers — the numbers of the apples Alexander likes.
Assume that the apples are numbered from 1 to *n*. The input is such that the answer exists. | Print *n* characters, each of them equals either 1 or 2. If the *i*-h character equals 1, then the *i*-th apple should be given to Arthur, otherwise it should be given to Alexander. If there are multiple correct answers, you are allowed to print any of them. | [
"4 2 3\n1 2\n2 3 4\n",
"5 5 2\n3 4 1 2 5\n2 3\n"
] | [
"1 1 2 2\n",
"1 1 1 1 1\n"
] | none | [
{
"input": "4 2 3\n1 2\n2 3 4",
"output": "1 1 2 2"
},
{
"input": "5 5 2\n3 4 1 2 5\n2 3",
"output": "1 1 1 1 1"
},
{
"input": "100 69 31\n1 3 4 5 6 7 8 9 10 11 12 14 15 16 17 18 19 20 21 24 26 27 29 31 37 38 39 40 44 46 48 49 50 51 53 55 56 57 58 59 60 61 63 64 65 66 67 68 69 70 71 72 7... | 62 | 5,529,600 | 3 | 932 | |
277 | Binary Tree on Plane | [
"flows",
"trees"
] | null | null | A root tree is a directed acyclic graph that contains one node (root), from which there is exactly one path to any other node.
A root tree is binary if each node has at most two outgoing arcs.
When a binary tree is painted on the plane, all arcs should be directed from top to bottom. That is, each arc going from *u* to *v* must meet the condition *y**u*<=><=*y**v*.
You've been given the coordinates of all tree nodes. Your task is to connect these nodes by arcs so as to get the binary root tree and make the total length of the arcs minimum. All arcs of the built tree must be directed from top to bottom. | The first line contains a single integer *n* (2<=≤<=*n*<=≤<=400) — the number of nodes in the tree. Then follow *n* lines, two integers per line: *x**i*,<=*y**i* (|*x**i*|,<=|*y**i*|<=≤<=103) — coordinates of the nodes. It is guaranteed that all points are distinct. | If it is impossible to build a binary root tree on the given points, print "-1". Otherwise, print a single real number — the total length of the arcs in the minimum binary tree. The answer will be considered correct if the absolute or relative error doesn't exceed 10<=-<=6. | [
"3\n0 0\n1 0\n2 1\n",
"4\n0 0\n1 0\n2 1\n2 0\n"
] | [
"3.650281539872885\n",
"-1\n"
] | none | [] | 3,000 | 70,758,400 | 0 | 933 | |
535 | Tavas and Karafs | [
"binary search",
"greedy",
"math"
] | null | null | Karafs is some kind of vegetable in shape of an 1<=×<=*h* rectangle. Tavaspolis people love Karafs and they use Karafs in almost any kind of food. Tavas, himself, is crazy about Karafs.
Each Karafs has a positive integer height. Tavas has an infinite 1-based sequence of Karafses. The height of the *i*-th Karafs is *s**i*<==<=*A*<=+<=(*i*<=-<=1)<=×<=*B*.
For a given *m*, let's define an *m*-bite operation as decreasing the height of at most *m* distinct not eaten Karafses by 1. Karafs is considered as eaten when its height becomes zero.
Now SaDDas asks you *n* queries. In each query he gives you numbers *l*, *t* and *m* and you should find the largest number *r* such that *l*<=≤<=*r* and sequence *s**l*,<=*s**l*<=+<=1,<=...,<=*s**r* can be eaten by performing *m*-bite no more than *t* times or print -1 if there is no such number *r*. | The first line of input contains three integers *A*, *B* and *n* (1<=≤<=*A*,<=*B*<=≤<=106, 1<=≤<=*n*<=≤<=105).
Next *n* lines contain information about queries. *i*-th line contains integers *l*,<=*t*,<=*m* (1<=≤<=*l*,<=*t*,<=*m*<=≤<=106) for *i*-th query. | For each query, print its answer in a single line. | [
"2 1 4\n1 5 3\n3 3 10\n7 10 2\n6 4 8\n",
"1 5 2\n1 5 10\n2 7 4\n"
] | [
"4\n-1\n8\n-1\n",
"1\n2\n"
] | none | [
{
"input": "2 1 4\n1 5 3\n3 3 10\n7 10 2\n6 4 8",
"output": "4\n-1\n8\n-1"
},
{
"input": "1 5 2\n1 5 10\n2 7 4",
"output": "1\n2"
},
{
"input": "1 1 4\n1 1000000 1000000\n1 1 1000000\n1 1000000 1\n1 1 1",
"output": "1000000\n1\n1413\n1"
},
{
"input": "1000000 1000000 1\n10000... | 2,000 | 0 | 0 | 936 | |
202 | LLPS | [
"binary search",
"bitmasks",
"brute force",
"greedy",
"implementation",
"strings"
] | null | null | This problem's actual name, "Lexicographically Largest Palindromic Subsequence" is too long to fit into the page headline.
You are given string *s* consisting of lowercase English letters only. Find its lexicographically largest palindromic subsequence.
We'll call a non-empty string *s*[*p*1*p*2... *p**k*] = *s**p*1*s**p*2... *s**p**k* (1 <=≤<= *p*1<=<<=*p*2<=<<=...<=<<=*p**k* <=≤<= |*s*|) a subsequence of string *s* = *s*1*s*2... *s*|*s*|, where |*s*| is the length of string *s*. For example, strings "abcb", "b" and "abacaba" are subsequences of string "abacaba".
String *x* = *x*1*x*2... *x*|*x*| is lexicographically larger than string *y* = *y*1*y*2... *y*|*y*| if either |*x*| > |*y*| and *x*1<==<=*y*1, *x*2<==<=*y*2, ...,<=*x*|*y*|<==<=*y*|*y*|, or there exists such number *r* (*r*<=<<=|*x*|, *r*<=<<=|*y*|) that *x*1<==<=*y*1, *x*2<==<=*y*2, ..., *x**r*<==<=*y**r* and *x**r*<=<=+<=<=1<=><=*y**r*<=<=+<=<=1. Characters in the strings are compared according to their ASCII codes. For example, string "ranger" is lexicographically larger than string "racecar" and string "poster" is lexicographically larger than string "post".
String *s* = *s*1*s*2... *s*|*s*| is a palindrome if it matches string *rev*(*s*) = *s*|*s*|*s*|*s*|<=-<=1... *s*1. In other words, a string is a palindrome if it reads the same way from left to right and from right to left. For example, palindromic strings are "racecar", "refer" and "z". | The only input line contains a non-empty string *s* consisting of lowercase English letters only. Its length does not exceed 10. | Print the lexicographically largest palindromic subsequence of string *s*. | [
"radar\n",
"bowwowwow\n",
"codeforces\n",
"mississipp\n"
] | [
"rr\n",
"wwwww\n",
"s\n",
"ssss\n"
] | Among all distinct subsequences of string "radar" the following ones are palindromes: "a", "d", "r", "aa", "rr", "ada", "rar", "rdr", "raar" and "radar". The lexicographically largest of them is "rr". | [
{
"input": "radar",
"output": "rr"
},
{
"input": "bowwowwow",
"output": "wwwww"
},
{
"input": "codeforces",
"output": "s"
},
{
"input": "mississipp",
"output": "ssss"
},
{
"input": "tourist",
"output": "u"
},
{
"input": "romka",
"output": "r"
},
... | 92 | 0 | 3 | 937 | |
952 | Ravioli Sort | [
"implementation"
] | null | null | Everybody knows of [spaghetti sort](https://en.wikipedia.org/wiki/Spaghetti_sort). You decided to implement an analog sorting algorithm yourself, but as you survey your pantry you realize you're out of spaghetti! The only type of pasta you have is ravioli, but you are not going to let this stop you...
You come up with the following algorithm. For each number in the array *a**i*, build a stack of *a**i* ravioli. The image shows the stack for *a**i*<==<=4.
Arrange the stacks in one row in the order in which the corresponding numbers appear in the input array. Find the tallest one (if there are several stacks of maximal height, use the leftmost one). Remove it and add its height to the end of the output array. Shift the stacks in the row so that there is no gap between them. Repeat the procedure until all stacks have been removed.
At first you are very happy with your algorithm, but as you try it on more inputs you realize that it doesn't always produce the right sorted array. Turns out when two stacks of ravioli are next to each other (at any step of the process) and differ in height by two or more, the top ravioli of the taller stack slides down on top of the lower stack.
Given an input array, figure out whether the described algorithm will sort it correctly. | The first line of input contains a single number *n* (1<=≤<=*n*<=≤<=10) — the size of the array.
The second line of input contains *n* space-separated integers *a**i* (1<=≤<=*a**i*<=≤<=100) — the elements of the array. | Output "YES" if the array can be sorted using the described procedure and "NO" if it can not. | [
"3\n1 2 3\n",
"3\n3 1 2\n"
] | [
"YES\n",
"NO\n"
] | In the second example the array will change even before the tallest stack is chosen for the first time: ravioli from stack of height 3 will slide on the stack of height 1, and the algorithm will output an array {2, 2, 2}. | [
{
"input": "3\n1 2 3",
"output": "YES"
},
{
"input": "3\n3 1 2",
"output": "NO"
},
{
"input": "1\n13",
"output": "YES"
},
{
"input": "10\n67 67 67 67 67 67 67 67 67 67",
"output": "YES"
},
{
"input": "10\n16 17 16 15 14 15 16 17 16 15",
"output": "YES"
},
... | 109 | 0 | 0 | 938 |
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