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622
The Sum of the k-th Powers
[ "math" ]
null
null
There are well-known formulas: , , . Also mathematicians found similar formulas for higher degrees. Find the value of the sum modulo 109<=+<=7 (so you should find the remainder after dividing the answer by the value 109<=+<=7).
The only line contains two integers *n*,<=*k* (1<=≤<=*n*<=≤<=109,<=0<=≤<=*k*<=≤<=106).
Print the only integer *a* — the remainder after dividing the value of the sum by the value 109<=+<=7.
[ "4 1\n", "4 2\n", "4 3\n", "4 0\n" ]
[ "10\n", "30\n", "100\n", "4\n" ]
none
[ { "input": "4 1", "output": "10" }, { "input": "4 2", "output": "30" }, { "input": "4 3", "output": "100" }, { "input": "4 0", "output": "4" }, { "input": "10 0", "output": "10" }, { "input": "1 1", "output": "1" }, { "input": "1 0", "o...
2,000
171,929,600
0
1,387
356
Knight Tournament
[ "data structures", "dsu" ]
null
null
Hooray! Berl II, the king of Berland is making a knight tournament. The king has already sent the message to all knights in the kingdom and they in turn agreed to participate in this grand event. As for you, you're just a simple peasant. There's no surprise that you slept in this morning and were late for the tourname...
The first line contains two integers *n*, *m* (2<=≤<=*n*<=≤<=3·105; 1<=≤<=*m*<=≤<=3·105) — the number of knights and the number of fights. Each of the following *m* lines contains three integers *l**i*,<=*r**i*,<=*x**i* (1<=≤<=*l**i*<=&lt;<=*r**i*<=≤<=*n*; *l**i*<=≤<=*x**i*<=≤<=*r**i*) — the description of the *i*-th f...
Print *n* integers. If the *i*-th knight lost, then the *i*-th number should equal the number of the knight that beat the knight number *i*. If the *i*-th knight is the winner, then the *i*-th number must equal 0.
[ "4 3\n1 2 1\n1 3 3\n1 4 4\n", "8 4\n3 5 4\n3 7 6\n2 8 8\n1 8 1\n" ]
[ "3 1 4 0 ", "0 8 4 6 4 8 6 1 " ]
Consider the first test case. Knights 1 and 2 fought the first fight and knight 1 won. Knights 1 and 3 fought the second fight and knight 3 won. The last fight was between knights 3 and 4, knight 4 won.
[ { "input": "4 3\n1 2 1\n1 3 3\n1 4 4", "output": "3 1 4 0 " }, { "input": "8 4\n3 5 4\n3 7 6\n2 8 8\n1 8 1", "output": "0 8 4 6 4 8 6 1 " }, { "input": "2 1\n1 2 1", "output": "0 1 " }, { "input": "2 1\n1 2 2", "output": "2 0 " }, { "input": "3 1\n1 3 1", "out...
31
0
0
1,391
225
Dice Tower
[ "constructive algorithms", "greedy" ]
null
null
A dice is a cube, its faces contain distinct integers from 1 to 6 as black points. The sum of numbers at the opposite dice faces always equals 7. Please note that there are only two dice (these dices are mirror of each other) that satisfy the given constraints (both of them are shown on the picture on the left). Alice...
The first line contains a single integer *n* (1<=≤<=*n*<=≤<=100) — the number of dice in the tower. The second line contains an integer *x* (1<=≤<=*x*<=≤<=6) — the number Bob sees at the top of the tower. Next *n* lines contain two space-separated integers each: the *i*-th line contains numbers *a**i*,<=*b**i* (1<=≤<=...
Print "YES" (without the quotes), if it is possible to to uniquely identify the numbers on the faces of all the dice in the tower. If it is impossible, print "NO" (without the quotes).
[ "3\n6\n3 2\n5 4\n2 4\n", "3\n3\n2 6\n4 1\n5 3\n" ]
[ "YES", "NO" ]
none
[ { "input": "3\n6\n3 2\n5 4\n2 4", "output": "YES" }, { "input": "3\n3\n2 6\n4 1\n5 3", "output": "NO" }, { "input": "1\n3\n2 1", "output": "YES" }, { "input": "2\n2\n3 1\n1 5", "output": "NO" }, { "input": "3\n2\n1 4\n5 3\n6 4", "output": "NO" }, { "in...
30
0
0
1,395
0
none
[ "none" ]
null
null
One day student Vasya was sitting on a lecture and mentioned a string *s*1*s*2... *s**n*, consisting of letters "a", "b" and "c" that was written on his desk. As the lecture was boring, Vasya decided to complete the picture by composing a graph *G* with the following properties: - *G* has exactly *n* vertices, numbe...
The first line of the input contains two integers *n* and *m*  — the number of vertices and edges in the graph found by Petya, respectively. Each of the next *m* lines contains two integers *u**i* and *v**i* (1<=≤<=*u**i*,<=*v**i*<=≤<=*n*,<=*u**i*<=≠<=*v**i*) — the edges of the graph *G*. It is guaranteed, that there ...
In the first line print "Yes" (without the quotes), if the string *s* Petya is interested in really exists and "No" (without the quotes) otherwise. If the string *s* exists, then print it on the second line of the output. The length of *s* must be exactly *n*, it must consist of only letters "a", "b" and "c" only, and...
[ "2 1\n1 2\n", "4 3\n1 2\n1 3\n1 4\n" ]
[ "Yes\naa\n", "No\n" ]
In the first sample you are given a graph made of two vertices with an edge between them. So, these vertices can correspond to both the same and adjacent letters. Any of the following strings "aa", "ab", "ba", "bb", "bc", "cb", "cc" meets the graph's conditions. In the second sample the first vertex is connected to a...
[ { "input": "2 1\n1 2", "output": "Yes\naa" }, { "input": "4 3\n1 2\n1 3\n1 4", "output": "No" }, { "input": "4 4\n1 2\n1 3\n1 4\n3 4", "output": "Yes\nbacc" }, { "input": "1 0", "output": "Yes\na" }, { "input": "8 28\n3 2\n4 2\n7 4\n6 3\n3 7\n8 1\n3 4\n5 1\n6 5\n5...
77
5,120,000
0
1,401
818
Card Game Again
[ "binary search", "data structures", "number theory", "two pointers" ]
null
null
Vova again tries to play some computer card game. The rules of deck creation in this game are simple. Vova is given an existing deck of *n* cards and a magic number *k*. The order of the cards in the deck is fixed. Each card has a number written on it; number *a**i* is written on the *i*-th card in the deck. After re...
The first line contains two integers *n* and *k* (1<=≤<=*n*<=≤<=100<=000, 1<=≤<=*k*<=≤<=109). The second line contains *n* integers *a*1, *a*2, ..., *a**n* (1<=≤<=*a**i*<=≤<=109) — the numbers written on the cards.
Print the number of ways to choose *x* and *y* so the resulting deck is valid.
[ "3 4\n6 2 8\n", "3 6\n9 1 14\n" ]
[ "4\n", "1\n" ]
In the first example the possible values of *x* and *y* are: 1. *x* = 0, *y* = 0; 1. *x* = 1, *y* = 0; 1. *x* = 2, *y* = 0; 1. *x* = 0, *y* = 1.
[ { "input": "3 4\n6 2 8", "output": "4" }, { "input": "3 6\n9 1 14", "output": "1" }, { "input": "5 1\n1 3 1 3 1", "output": "15" }, { "input": "5 1\n5 5 5 5 5", "output": "15" }, { "input": "5 1\n5 4 4 4 4", "output": "15" }, { "input": "100 1\n1 1 1 1...
77
7,065,600
0
1,404
831
Unimodal Array
[ "implementation" ]
null
null
Array of integers is unimodal, if: - it is strictly increasing in the beginning; - after that it is constant; - after that it is strictly decreasing. The first block (increasing) and the last block (decreasing) may be absent. It is allowed that both of this blocks are absent. For example, the following three arra...
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*<=≤<=1<=000) — the elements of the array.
Print "YES" if the given array is unimodal. Otherwise, print "NO". You can output each letter in any case (upper or lower).
[ "6\n1 5 5 5 4 2\n", "5\n10 20 30 20 10\n", "4\n1 2 1 2\n", "7\n3 3 3 3 3 3 3\n" ]
[ "YES\n", "YES\n", "NO\n", "YES\n" ]
In the first example the array is unimodal, because it is strictly increasing in the beginning (from position 1 to position 2, inclusively), that it is constant (from position 2 to position 4, inclusively) and then it is strictly decreasing (from position 4 to position 6, inclusively).
[ { "input": "6\n1 5 5 5 4 2", "output": "YES" }, { "input": "5\n10 20 30 20 10", "output": "YES" }, { "input": "4\n1 2 1 2", "output": "NO" }, { "input": "7\n3 3 3 3 3 3 3", "output": "YES" }, { "input": "6\n5 7 11 11 2 1", "output": "YES" }, { "input":...
15
0
0
1,405
32
Reconnaissance
[ "brute force" ]
A. Reconnaissance
2
256
According to the regulations of Berland's army, a reconnaissance unit should consist of exactly two soldiers. Since these two soldiers shouldn't differ much, their heights can differ by at most *d* centimeters. Captain Bob has *n* soldiers in his detachment. Their heights are *a*1,<=*a*2,<=...,<=*a**n* centimeters. Som...
The first line contains two integers *n* and *d* (1<=≤<=*n*<=≤<=1000,<=1<=≤<=*d*<=≤<=109) — amount of soldiers in Bob's detachment and the maximum allowed height difference respectively. The second line contains *n* space-separated integers — heights of all the soldiers in Bob's detachment. These numbers don't exceed 1...
Output one number — amount of ways to form a reconnaissance unit of two soldiers, whose height difference doesn't exceed *d*.
[ "5 10\n10 20 50 60 65\n", "5 1\n55 30 29 31 55\n" ]
[ "6\n", "6\n" ]
none
[ { "input": "5 10\n10 20 50 60 65", "output": "6" }, { "input": "5 1\n55 30 29 31 55", "output": "6" }, { "input": "6 10\n4 6 4 1 9 3", "output": "30" }, { "input": "7 100\n19 1694 261 162 1 234 513", "output": "8" }, { "input": "8 42\n37 53 74 187 568 22 5 65", ...
62
0
0
1,409
262
Roma and Lucky Numbers
[ "implementation" ]
null
null
Roma (a popular Russian name that means 'Roman') loves the Little Lvov Elephant's lucky numbers. Let us remind you that lucky numbers are positive integers whose decimal representation only contains lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not. Roma's got *n* positive integer...
The first line contains two integers *n*, *k* (1<=≤<=*n*,<=*k*<=≤<=100). The second line contains *n* integers *a**i* (1<=≤<=*a**i*<=≤<=109) — the numbers that Roma has. The numbers in the lines are separated by single spaces.
In a single line print a single integer — the answer to the problem.
[ "3 4\n1 2 4\n", "3 2\n447 44 77\n" ]
[ "3\n", "2\n" ]
In the first sample all numbers contain at most four lucky digits, so the answer is 3. In the second sample number 447 doesn't fit in, as it contains more than two lucky digits. All other numbers are fine, so the answer is 2.
[ { "input": "3 4\n1 2 4", "output": "3" }, { "input": "3 2\n447 44 77", "output": "2" }, { "input": "2 2\n507978501 180480073", "output": "2" }, { "input": "9 6\n655243746 167613748 1470546 57644035 176077477 56984809 44677 215706823 369042089", "output": "9" }, { ...
186
6,656,000
3
1,411
801
Vicious Keyboard
[ "brute force" ]
null
null
Tonio has a keyboard with only two letters, "V" and "K". One day, he has typed out a string *s* with only these two letters. He really likes it when the string "VK" appears, so he wishes to change at most one letter in the string (or do no changes) to maximize the number of occurrences of that string. Compute the maxi...
The first line will contain a string *s* consisting only of uppercase English letters "V" and "K" with length not less than 1 and not greater than 100.
Output a single integer, the maximum number of times "VK" can appear as a substring of the given string after changing at most one character.
[ "VK\n", "VV\n", "V\n", "VKKKKKKKKKVVVVVVVVVK\n", "KVKV\n" ]
[ "1\n", "1\n", "0\n", "3\n", "1\n" ]
For the first case, we do not change any letters. "VK" appears once, which is the maximum number of times it could appear. For the second case, we can change the second character from a "V" to a "K". This will give us the string "VK". This has one occurrence of the string "VK" as a substring. For the fourth case, we ...
[ { "input": "VK", "output": "1" }, { "input": "VV", "output": "1" }, { "input": "V", "output": "0" }, { "input": "VKKKKKKKKKVVVVVVVVVK", "output": "3" }, { "input": "KVKV", "output": "1" }, { "input": "VKKVVVKVKVK", "output": "5" }, { "input...
77
5,529,600
3
1,413
637
Chat Order
[ "*special", "binary search", "constructive algorithms", "data structures", "sortings" ]
null
null
Polycarp is a big lover of killing time in social networks. A page with a chatlist in his favourite network is made so that when a message is sent to some friend, his friend's chat rises to the very top of the page. The relative order of the other chats doesn't change. If there was no chat with this friend before, then...
The first line contains integer *n* (1<=≤<=*n*<=≤<=200<=000) — the number of Polycarpus' messages. Next *n* lines enlist the message recipients in the order in which the messages were sent. The name of each participant is a non-empty sequence of lowercase English letters of length at most 10.
Print all the recipients to who Polycarp talked to in the order of chats with them, from top to bottom.
[ "4\nalex\nivan\nroman\nivan\n", "8\nalina\nmaria\nekaterina\ndarya\ndarya\nekaterina\nmaria\nalina\n" ]
[ "ivan\nroman\nalex\n", "alina\nmaria\nekaterina\ndarya\n" ]
In the first test case Polycarpus first writes to friend by name "alex", and the list looks as follows: 1. alex Then Polycarpus writes to friend by name "ivan" and the list looks as follows: 1. ivan 1. alex Polycarpus writes the third message to friend by name "roman" and the list looks as follows: 1. roman 1...
[ { "input": "4\nalex\nivan\nroman\nivan", "output": "ivan\nroman\nalex" }, { "input": "8\nalina\nmaria\nekaterina\ndarya\ndarya\nekaterina\nmaria\nalina", "output": "alina\nmaria\nekaterina\ndarya" }, { "input": "1\nwdi", "output": "wdi" }, { "input": "2\nypg\nypg", "outpu...
514
28,569,600
3
1,416
104
Blackjack
[ "implementation" ]
A. Blackjack
2
256
One rainy gloomy evening when all modules hid in the nearby cafes to drink hot energetic cocktails, the Hexadecimal virus decided to fly over the Mainframe to look for a Great Idea. And she has found one! Why not make her own Codeforces, with blackjack and other really cool stuff? Many people will surely be willing to...
The only line contains *n* (1<=≤<=*n*<=≤<=25) — the required sum of points.
Print the numbers of ways to get the second card in the required way if the first card is the queen of spades.
[ "12\n", "20\n", "10\n" ]
[ "4", "15", "0" ]
In the first sample only four two's of different suits can earn the required sum of points. In the second sample we can use all tens, jacks, queens and kings; overall it's 15 cards, as the queen of spades (as any other card) is only present once in the pack of cards and it's already in use. In the third sample there ...
[ { "input": "12", "output": "4" }, { "input": "20", "output": "15" }, { "input": "10", "output": "0" }, { "input": "11", "output": "4" }, { "input": "15", "output": "4" }, { "input": "18", "output": "4" }, { "input": "25", "output": "0" ...
122
4,710,400
0
1,417
914
Substrings in a String
[ "bitmasks", "brute force", "data structures", "string suffix structures", "strings" ]
null
null
Given a string *s*, process *q* queries, each having one of the following forms: - 1<=*i*<=*c* — Change the *i*-th character in the string to *c*. - 2<=*l*<=*r*<=*y* — Consider the substring of *s* starting at position *l* and ending at position *r*. Output the number of times *y* occurs as a substring in it.
The first line of the input contains the string *s* (1<=≤<=|*s*|<=≤<=105) of lowercase English letters. The second line contains an integer *q* (1<=≤<=*q*<=≤<=105)  — the number of queries to process. The next *q* lines describe the queries and may have one of the following forms: - 1<=*i*<=*c* (1<=≤<=*i*<=≤<=|*s*|...
For each query of type 2, output the required answer in a separate line.
[ "ababababa\n3\n2 1 7 aba\n1 5 c\n2 1 7 aba\n", "abcdcbc\n5\n2 1 7 bc\n1 4 b\n2 4 7 bc\n1 2 a\n2 1 4 aa\n" ]
[ "3\n1\n", "2\n2\n1\n" ]
Consider the first sample case. Initially, the string aba occurs 3 times in the range [1, 7]. Note that two occurrences may overlap. After the update, the string becomes ababcbaba and now aba occurs only once in the range [1, 7].
[]
15
0
0
1,418
479
Expression
[ "brute force", "math" ]
null
null
Petya studies in a school and he adores Maths. His class has been studying arithmetic expressions. On the last class the teacher wrote three positive integers *a*, *b*, *c* on the blackboard. The task was to insert signs of operations '+' and '*', and probably brackets between the numbers so that the value of the resul...
The input contains three integers *a*, *b* and *c*, each on a single line (1<=≤<=*a*,<=*b*,<=*c*<=≤<=10).
Print the maximum value of the expression that you can obtain.
[ "1\n2\n3\n", "2\n10\n3\n" ]
[ "9\n", "60\n" ]
none
[ { "input": "1\n2\n3", "output": "9" }, { "input": "2\n10\n3", "output": "60" }, { "input": "1\n1\n1", "output": "3" }, { "input": "1\n2\n1", "output": "4" }, { "input": "10\n10\n10", "output": "1000" }, { "input": "5\n1\n3", "output": "20" }, {...
31
0
-1
1,420
14
Young Photographer
[ "implementation" ]
B. Young Photographer
2
64
Among other things, Bob is keen on photography. Especially he likes to take pictures of sportsmen. That was the reason why he placed himself in position *x*0 of a long straight racetrack and got ready to take pictures. But the problem was that not all the runners passed him. The total amount of sportsmen, training at t...
The first line of the input file contains integers *n* and *x*0 (1<=≤<=*n*<=≤<=100; 0<=≤<=*x*0<=≤<=1000). The following *n* lines contain pairs of integers *a**i*,<=*b**i* (0<=≤<=*a**i*,<=*b**i*<=≤<=1000; *a**i*<=≠<=*b**i*).
Output the required minimum distance in the same units as the positions on the racetrack. If there is no such a position, output -1.
[ "3 3\n0 7\n14 2\n4 6\n" ]
[ "1\n" ]
none
[ { "input": "3 3\n0 7\n14 2\n4 6", "output": "1" }, { "input": "1 1\n0 10", "output": "0" }, { "input": "2 2\n1 2\n3 2", "output": "0" }, { "input": "3 2\n1 2\n2 3\n3 4", "output": "-1" }, { "input": "2 4\n10 4\n1 5", "output": "0" }, { "input": "1 10\n...
310
3,584,000
0
1,421
158
Taxi
[ "*special", "greedy", "implementation" ]
null
null
After the lessons *n* groups of schoolchildren went outside and decided to visit Polycarpus to celebrate his birthday. We know that the *i*-th group consists of *s**i* friends (1<=≤<=*s**i*<=≤<=4), and they want to go to Polycarpus together. They decided to get there by taxi. Each car can carry at most four passengers....
The first line contains integer *n* (1<=≤<=*n*<=≤<=105) — the number of groups of schoolchildren. The second line contains a sequence of integers *s*1,<=*s*2,<=...,<=*s**n* (1<=≤<=*s**i*<=≤<=4). The integers are separated by a space, *s**i* is the number of children in the *i*-th group.
Print the single number — the minimum number of taxis necessary to drive all children to Polycarpus.
[ "5\n1 2 4 3 3\n", "8\n2 3 4 4 2 1 3 1\n" ]
[ "4\n", "5\n" ]
In the first test we can sort the children into four cars like this: - the third group (consisting of four children), - the fourth group (consisting of three children), - the fifth group (consisting of three children), - the first and the second group (consisting of one and two children, correspondingly). There a...
[ { "input": "5\n1 2 4 3 3", "output": "4" }, { "input": "8\n2 3 4 4 2 1 3 1", "output": "5" }, { "input": "5\n4 4 4 4 4", "output": "5" }, { "input": "12\n1 1 1 1 1 1 1 1 1 1 1 1", "output": "3" }, { "input": "2\n2 1", "output": "1" }, { "input": "4\n3 ...
156
3,481,600
3
1,430
149
Division into Teams
[ "greedy", "math", "sortings" ]
null
null
Petya loves football very much, especially when his parents aren't home. Each morning he comes to the yard, gathers his friends and they play all day. From time to time they have a break to have some food or do some chores (for example, water the flowers). The key in football is to divide into teams fairly before the ...
The first line contains the only integer *n* (2<=≤<=*n*<=≤<=105) which represents the number of guys in the yard. The next line contains *n* positive space-separated integers, *a**i* (1<=≤<=*a**i*<=≤<=104), the *i*-th number represents the *i*-th boy's playing skills.
On the first line print an integer *x* — the number of boys playing for the first team. On the second line print *x* integers — the individual numbers of boys playing for the first team. On the third line print an integer *y* — the number of boys playing for the second team, on the fourth line print *y* integers — the ...
[ "3\n1 2 1\n", "5\n2 3 3 1 1\n" ]
[ "2\n1 2 \n1\n3 \n", "3\n4 1 3 \n2\n5 2 \n" ]
Let's consider the first sample test. There we send the first and the second boy to the first team and the third boy to the second team. Let's check all three conditions of a fair division. The first limitation is fulfilled (all boys play), the second limitation on the sizes of groups (|2 - 1| = 1 ≤ 1) is fulfilled, th...
[ { "input": "3\n1 2 1", "output": "2\n1 2 \n1\n3 " }, { "input": "5\n2 3 3 1 1", "output": "3\n4 1 3 \n2\n5 2 " }, { "input": "10\n2 2 2 2 2 2 2 1 2 2", "output": "5\n8 2 4 6 9 \n5\n1 3 5 7 10 " }, { "input": "10\n2 3 3 1 3 1 1 1 2 2", "output": "5\n4 7 1 10 3 \n5\n6 8 9 2...
280
9,830,400
3
1,431
54
Presents
[ "implementation" ]
A. Presents
2
256
The Hedgehog likes to give presents to his friend, but no less he likes to receive them. Having received another present today, the Hedgehog suddenly understood that he has no place to put it as there was no room left on the special shelf in the cupboard. He will have to choose another shelf, but which one should he c...
The first line contains integers *N* and *K* (1<=≤<=*N*<=≤<=365, 1<=≤<=*K*<=≤<=*N*). The second line contains a number *C* which represents the number of holidays (0<=≤<=*C*<=≤<=*N*). Then in the same line follow *C* numbers ranging from 1 to *N* which are the numbers of holiday days. The numbers are given in the incr...
Print a single number — the minimal number of presents the Hedgehog will receive over the following *N* days.
[ "5 2\n1 3\n", "10 1\n3 6 7 8\n" ]
[ "3", "10" ]
none
[ { "input": "5 2\n1 3", "output": "3" }, { "input": "10 1\n3 6 7 8", "output": "10" }, { "input": "5 5\n1 3", "output": "1" }, { "input": "10 3\n3 3 6 9", "output": "3" }, { "input": "5 2\n0", "output": "2" }, { "input": "1 1\n0", "output": "1" },...
62
0
0
1,433
471
MUH and Cube Walls
[ "string suffix structures", "strings" ]
null
null
Polar bears Menshykov and Uslada from the zoo of St. Petersburg and elephant Horace from the zoo of Kiev got hold of lots of wooden cubes somewhere. They started making cube towers by placing the cubes one on top of the other. They defined multiple towers standing in a line as a wall. A wall can consist of towers of di...
The first line contains two integers *n* and *w* (1<=≤<=*n*,<=*w*<=≤<=2·105) — the number of towers in the bears' and the elephant's walls correspondingly. The second line contains *n* integers *a**i* (1<=≤<=*a**i*<=≤<=109) — the heights of the towers in the bears' wall. The third line contains *w* integers *b**i* (1<=...
Print the number of segments in the bears' wall where Horace can "see an elephant".
[ "13 5\n2 4 5 5 4 3 2 2 2 3 3 2 1\n3 4 4 3 2\n" ]
[ "2" ]
The picture to the left shows Horace's wall from the sample, the picture to the right shows the bears' wall. The segments where Horace can "see an elephant" are in gray.
[ { "input": "13 5\n2 4 5 5 4 3 2 2 2 3 3 2 1\n3 4 4 3 2", "output": "2" }, { "input": "5 1\n8 71 1 24 2\n31", "output": "5" }, { "input": "6 3\n2 2 2 2 2 2\n5 5 5", "output": "4" }, { "input": "1 1\n576560149\n691846236", "output": "1" }, { "input": "10 5\n5 10 8 1...
15
0
-1
1,436
436
Feed with Candy
[ "greedy" ]
null
null
The hero of the Cut the Rope game is a little monster named Om Nom. He loves candies. And what a coincidence! He also is the hero of today's problem. One day, Om Nom visited his friend Evan. Evan has *n* candies of two types (fruit drops and caramel drops), the *i*-th candy hangs at the height of *h**i* centimeters ab...
The first line contains two integers, *n* and *x* (1<=≤<=*n*,<=*x*<=≤<=2000) — the number of sweets Evan has and the initial height of Om Nom's jump. Each of the following *n* lines contains three integers *t**i*,<=*h**i*,<=*m**i* (0<=≤<=*t**i*<=≤<=1; 1<=≤<=*h**i*,<=*m**i*<=≤<=2000) — the type, height and the mass of...
Print a single integer — the maximum number of candies Om Nom can eat.
[ "5 3\n0 2 4\n1 3 1\n0 8 3\n0 20 10\n1 5 5\n" ]
[ "4\n" ]
One of the possible ways to eat 4 candies is to eat them in the order: 1, 5, 3, 2. Let's assume the following scenario: 1. Initially, the height of Om Nom's jump equals 3. He can reach candies 1 and 2. Let's assume that he eats candy 1. As the mass of this candy equals 4, the height of his jump will rise to 3 + 4 = 7...
[ { "input": "5 3\n0 2 4\n1 3 1\n0 8 3\n0 20 10\n1 5 5", "output": "4" }, { "input": "5 2\n1 15 2\n1 11 2\n0 17 2\n0 16 1\n1 18 2", "output": "0" }, { "input": "6 2\n1 17 3\n1 6 1\n0 4 2\n1 10 1\n1 7 3\n1 5 1", "output": "0" }, { "input": "7 2\n1 14 1\n1 9 2\n0 6 3\n0 20 2\n0 4...
545
819,200
3
1,438
842
Gleb And Pizza
[ "geometry" ]
null
null
Gleb ordered pizza home. When the courier delivered the pizza, he was very upset, because several pieces of sausage lay on the crust, and he does not really like the crust. The pizza is a circle of radius *r* and center at the origin. Pizza consists of the main part — circle of radius *r*<=-<=*d* with center at the or...
First string contains two integer numbers *r* and *d* (0<=≤<=*d*<=&lt;<=*r*<=≤<=500) — the radius of pizza and the width of crust. Next line contains one integer number *n* — the number of pieces of sausage (1<=≤<=*n*<=≤<=105). Each of next *n* lines contains three integer numbers *x**i*, *y**i* and *r**i* (<=-<=500<...
Output the number of pieces of sausage that lay on the crust.
[ "8 4\n7\n7 8 1\n-7 3 2\n0 2 1\n0 -2 2\n-3 -3 1\n0 6 2\n5 3 1\n", "10 8\n4\n0 0 9\n0 0 10\n1 0 1\n1 0 2\n" ]
[ "2\n", "0\n" ]
Below is a picture explaining the first example. Circles of green color denote pieces of sausage lying on the crust.
[ { "input": "8 4\n7\n7 8 1\n-7 3 2\n0 2 1\n0 -2 2\n-3 -3 1\n0 6 2\n5 3 1", "output": "2" }, { "input": "10 8\n4\n0 0 9\n0 0 10\n1 0 1\n1 0 2", "output": "0" }, { "input": "1 0\n1\n1 1 0", "output": "0" }, { "input": "3 0\n5\n3 0 0\n0 3 0\n-3 0 0\n0 -3 0\n3 0 1", "output": ...
124
0
0
1,439
813
Army Creation
[ "binary search", "data structures" ]
null
null
As you might remember from our previous rounds, Vova really likes computer games. Now he is playing a strategy game known as Rage of Empires. In the game Vova can hire *n* different warriors; *i*th warrior has the type *a**i*. Vova wants to create a balanced army hiring some subset of warriors. An army is called balan...
The first line contains two integers *n* and *k* (1<=≤<=*n*,<=*k*<=≤<=100000). The second line contains *n* integers *a*1, *a*2, ... *a**n* (1<=≤<=*a**i*<=≤<=100000). The third line contains one integer *q* (1<=≤<=*q*<=≤<=100000). Then *q* lines follow. *i*th line contains two numbers *x**i* and *y**i* which represe...
Print *q* numbers. *i*th number must be equal to the maximum size of a balanced army when considering *i*th plan.
[ "6 2\n1 1 1 2 2 2\n5\n1 6\n4 3\n1 1\n2 6\n2 6\n" ]
[ "2\n4\n1\n3\n2\n" ]
In the first example the real plans are: 1. 1 2 1. 1 6 1. 6 6 1. 2 4 1. 4 6
[ { "input": "6 2\n1 1 1 2 2 2\n5\n1 6\n4 3\n1 1\n2 6\n2 6", "output": "2\n4\n1\n3\n2" }, { "input": "5 5\n3 4 4 2 1\n5\n5 5\n5 4\n5 4\n3 4\n5 5", "output": "1\n2\n2\n2\n1" }, { "input": "5 5\n2 1 2 4 1\n5\n5 3\n1 1\n5 1\n2 1\n2 3", "output": "4\n1\n2\n2\n5" }, { "input": "10 5...
46
0
0
1,441
681
A Good Contest
[ "implementation" ]
null
null
Codeforces user' handle color depends on his rating — it is red if his rating is greater or equal to 2400; it is orange if his rating is less than 2400 but greater or equal to 2200, etc. Each time participant takes part in a rated contest, his rating is changed depending on his performance. Anton wants the color of hi...
The first line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=100) — the number of participants Anton has outscored in this contest . The next *n* lines describe participants results: the *i*-th of them consists of a participant handle *name**i* and two integers *before**i* and *after**i* (<=-<=4000<=≤<=*be...
Print «YES» (quotes for clarity), if Anton has performed good in the contest and «NO» (quotes for clarity) otherwise.
[ "3\nBurunduk1 2526 2537\nBudAlNik 2084 2214\nsubscriber 2833 2749\n", "3\nApplejack 2400 2400\nFluttershy 2390 2431\nPinkie_Pie -2500 -2450\n" ]
[ "YES", "NO" ]
In the first sample, Anton has outscored user with handle Burunduk1, whose handle was colored red before the contest and his rating has increased after the contest. In the second sample, Applejack's rating has not increased after the contest, while both Fluttershy's and Pinkie_Pie's handles were not colored red before...
[ { "input": "3\nBurunduk1 2526 2537\nBudAlNik 2084 2214\nsubscriber 2833 2749", "output": "YES" }, { "input": "3\nApplejack 2400 2400\nFluttershy 2390 2431\nPinkie_Pie -2500 -2450", "output": "NO" }, { "input": "1\nDb -3373 3591", "output": "NO" }, { "input": "5\nQ2bz 960 2342...
0
0
-1
1,442
592
PawnChess
[ "implementation" ]
null
null
Galois is one of the strongest chess players of Byteforces. He has even invented a new variant of chess, which he named «PawnChess». This new game is played on a board consisting of 8 rows and 8 columns. At the beginning of every game some black and white pawns are placed on the board. The number of black pawns placed...
The input consists of the board description given in eight lines, each line contains eight characters. Character 'B' is used to denote a black pawn, and character 'W' represents a white pawn. Empty cell is marked with '.'. It's guaranteed that there will not be white pawns on the first row neither black pawns on the ...
Print 'A' if player A wins the game on the given board, and 'B' if player B will claim the victory. Again, it's guaranteed that there will always be a winner on the given board.
[ "........\n........\n.B....B.\n....W...\n........\n..W.....\n........\n........\n", "..B.....\n..W.....\n......B.\n........\n.....W..\n......B.\n........\n........\n" ]
[ "A\n", "B\n" ]
In the first sample player A is able to complete his goal in 3 steps by always moving a pawn initially located at (4, 5). Player B needs at least 5 steps for any of his pawns to reach the row 8. Hence, player A will be the winner.
[ { "input": ".BB.B.B.\nB..B..B.\n.B.BB...\nBB.....B\nBBB....B\nB..BB...\nBB.B...B\n....WWW.", "output": "B" }, { "input": "B.B.BB.B\nW.WWW.WW\n.WWWWW.W\nW.BB.WBW\n.W..BBWB\nBB.WWBBB\n.W.W.WWB\nWWW..WW.", "output": "A" }, { "input": "BB..BB..\nBW.W.W.B\n..B.....\n.....BB.\n.B..B..B\n.........
109
23,142,400
3
1,446
1,009
Intercity Travelling
[ "combinatorics", "math", "probabilities" ]
null
null
Leha is planning his journey from Moscow to Saratov. He hates trains, so he has decided to get from one city to another by car. The path from Moscow to Saratov can be represented as a straight line (well, it's not that straight in reality, but in this problem we will consider it to be straight), and the distance betwe...
The first line contains one number $n$ ($1 \le n \le 10^6$) — the distance from Moscow to Saratov. The second line contains $n$ integer numbers $a_1$, $a_2$, ..., $a_n$ ($1 \le a_1 \le a_2 \le \dots \le a_n \le 10^6$), where $a_i$ is the difficulty of $i$-th kilometer after Leha has rested.
Print one number — $p \cdot 2^{n - 1}$, taken modulo $998244353$.
[ "2\n1 2\n", "4\n1 3 3 7\n" ]
[ "5\n", "60\n" ]
none
[ { "input": "2\n1 2", "output": "5" }, { "input": "4\n1 3 3 7", "output": "60" }, { "input": "100\n3 3 3 4 7 8 8 8 9 9 10 12 12 13 14 14 15 15 16 17 17 20 21 21 22 22 23 25 29 31 36 37 37 38 39 40 41 41 41 42 43 44 45 46 46 47 47 49 49 49 51 52 52 53 54 55 59 59 59 60 62 63 63 64 66 69 70...
93
0
0
1,449
960
Subsequence Counting
[ "bitmasks", "constructive algorithms", "greedy", "implementation" ]
null
null
Pikachu had an array with him. He wrote down all the non-empty subsequences of the array on paper. Note that an array of size *n* has 2*n*<=-<=1 non-empty subsequences in it. Pikachu being mischievous as he always is, removed all the subsequences in which Maximum_element_of_the_subsequence <=-<= Minimum_element_of_su...
The only line of input consists of two space separated integers *X* and *d* (1<=≤<=*X*,<=*d*<=≤<=109).
Output should consist of two lines. First line should contain a single integer *n* (1<=≤<=*n*<=≤<=10<=000)— the number of integers in the final array. Second line should consist of *n* space separated integers — *a*1,<=*a*2,<=... ,<=*a**n* (1<=≤<=*a**i*<=&lt;<=1018). If there is no answer, print a single integer -1....
[ "10 5\n", "4 2\n" ]
[ "6\n5 50 7 15 6 100", "4\n10 100 1000 10000" ]
In the output of the first example case, the remaining subsequences after removing those with Maximum_element_of_the_subsequence  -  Minimum_element_of_subsequence  ≥ 5 are [5], [5, 7], [5, 6], [5, 7, 6], [50], [7], [7, 6], [15], [6], [100]. There are 10 of them. Hence, the array [5, 50, 7, 15, 6, 100] is valid. Simil...
[ { "input": "10 5", "output": "6\n1 1 1 7 13 19 " }, { "input": "4 2", "output": "3\n1 1 4 " }, { "input": "4 1", "output": "3\n1 1 3 " }, { "input": "1 1", "output": "1\n1 " }, { "input": "63 1", "output": "21\n1 1 1 1 1 3 3 3 3 5 5 5 7 7 9 11 13 15 17 19 21 "...
1,000
102,400
0
1,450
721
Journey
[ "dp", "graphs" ]
null
null
Recently Irina arrived to one of the most famous cities of Berland — the Berlatov city. There are *n* showplaces in the city, numbered from 1 to *n*, and some of them are connected by one-directional roads. The roads in Berlatov are designed in a way such that there are no cyclic routes between showplaces. Initially I...
The first line of the input contains three integers *n*,<=*m* and *T* (2<=≤<=*n*<=≤<=5000,<=<=1<=≤<=*m*<=≤<=5000,<=<=1<=≤<=*T*<=≤<=109) — the number of showplaces, the number of roads between them and the time of Irina's stay in Berlatov respectively. The next *m* lines describes roads in Berlatov. *i*-th of them cont...
Print the single integer *k* (2<=≤<=*k*<=≤<=*n*) — the maximum number of showplaces that Irina can visit during her journey from showplace 1 to showplace *n* within time not exceeding *T*, in the first line. Print *k* distinct integers in the second line — indices of showplaces that Irina will visit on her route, in t...
[ "4 3 13\n1 2 5\n2 3 7\n2 4 8\n", "6 6 7\n1 2 2\n1 3 3\n3 6 3\n2 4 2\n4 6 2\n6 5 1\n", "5 5 6\n1 3 3\n3 5 3\n1 2 2\n2 4 3\n4 5 2\n" ]
[ "3\n1 2 4 \n", "4\n1 2 4 6 \n", "3\n1 3 5 \n" ]
none
[ { "input": "4 3 13\n1 2 5\n2 3 7\n2 4 8", "output": "3\n1 2 4 " }, { "input": "6 6 7\n1 2 2\n1 3 3\n3 6 3\n2 4 2\n4 6 2\n6 5 1", "output": "4\n1 2 4 6 " }, { "input": "5 5 6\n1 3 3\n3 5 3\n1 2 2\n2 4 3\n4 5 2", "output": "3\n1 3 5 " }, { "input": "10 10 100\n1 4 1\n6 4 1\n9 3...
3,000
103,628,800
0
1,454
964
Splits
[ "math" ]
null
null
Let's define a split of $n$ as a nonincreasing sequence of positive integers, the sum of which is $n$. For example, the following sequences are splits of $8$: $[4, 4]$, $[3, 3, 2]$, $[2, 2, 1, 1, 1, 1]$, $[5, 2, 1]$. The following sequences aren't splits of $8$: $[1, 7]$, $[5, 4]$, $[11, -3]$, $[1, 1, 4, 1, 1]$. Th...
The first line contains one integer $n$ ($1 \leq n \leq 10^9$).
Output one integer — the answer to the problem.
[ "7\n", "8\n", "9\n" ]
[ "4\n", "5\n", "5\n" ]
In the first sample, there are following possible weights of splits of $7$: Weight 1: [$\textbf 7$] Weight 2: [$\textbf 3$, $\textbf 3$, 1] Weight 3: [$\textbf 2$, $\textbf 2$, $\textbf 2$, 1] Weight 7: [$\textbf 1$, $\textbf 1$, $\textbf 1$, $\textbf 1$, $\textbf 1$, $\textbf 1$, $\textbf 1$]
[ { "input": "7", "output": "4" }, { "input": "8", "output": "5" }, { "input": "9", "output": "5" }, { "input": "1", "output": "1" }, { "input": "286", "output": "144" }, { "input": "48", "output": "25" }, { "input": "941", "output": "471...
0
0
-1
1,455
595
Vitaly and Night
[ "constructive algorithms", "implementation" ]
null
null
One day Vitaly was going home late at night and wondering: how many people aren't sleeping at that moment? To estimate, Vitaly decided to look which windows are lit in the house he was passing by at that moment. Vitaly sees a building of *n* floors and 2·*m* windows on each floor. On each floor there are *m* flats num...
The first line of the input contains two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=100) — the number of floors in the house and the number of flats on each floor respectively. Next *n* lines describe the floors from top to bottom and contain 2·*m* characters each. If the *i*-th window of the given floor has lights on,...
Print a single integer — the number of flats that have lights on in at least one window, that is, the flats where, according to Vitaly, people aren't sleeping.
[ "2 2\n0 0 0 1\n1 0 1 1\n", "1 3\n1 1 0 1 0 0\n" ]
[ "3\n", "2\n" ]
In the first test case the house has two floors, two flats on each floor. That is, in total there are 4 flats. The light isn't on only on the second floor in the left flat. That is, in both rooms of the flat the light is off. In the second test case the house has one floor and the first floor has three flats. The ligh...
[ { "input": "2 2\n0 0 0 1\n1 0 1 1", "output": "3" }, { "input": "1 3\n1 1 0 1 0 0", "output": "2" }, { "input": "3 3\n1 1 1 1 1 1\n1 1 0 1 1 0\n1 0 0 0 1 1", "output": "8" }, { "input": "1 5\n1 0 1 1 1 0 1 1 1 1", "output": "5" }, { "input": "1 100\n1 1 1 1 1 1 1 ...
155
614,400
3
1,456
446
DZY Loves Fibonacci Numbers
[ "data structures", "math", "number theory" ]
null
null
In mathematical terms, the sequence *F**n* of Fibonacci numbers is defined by the recurrence relation DZY loves Fibonacci numbers very much. Today DZY gives you an array consisting of *n* integers: *a*1,<=*a*2,<=...,<=*a**n*. Moreover, there are *m* queries, each query has one of the two types: 1. Format of the que...
The first line of the input contains two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=300000). The second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=109) — initial array *a*. Then, *m* lines follow. A single line describes a single query in the format given in the statement. It is guaranteed ...
For each query of the second type, print the value of the sum on a single line.
[ "4 4\n1 2 3 4\n1 1 4\n2 1 4\n1 2 4\n2 1 3\n" ]
[ "17\n12\n" ]
After the first query, *a* = [2, 3, 5, 7]. For the second query, *sum* = 2 + 3 + 5 + 7 = 17. After the third query, *a* = [2, 4, 6, 9]. For the fourth query, *sum* = 2 + 4 + 6 = 12.
[ { "input": "4 4\n1 2 3 4\n1 1 4\n2 1 4\n1 2 4\n2 1 3", "output": "17\n12" }, { "input": "2 2\n1 2\n2 1 2\n2 1 2", "output": "3\n3" }, { "input": "10 20\n56 12 68 23 41 29 97 69 79 76\n1 3 5\n1 8 9\n2 3 10\n1 7 10\n2 1 10\n1 5 10\n2 2 4\n1 2 4\n1 5 6\n2 1 2\n2 4 5\n1 1 5\n1 8 9\n2 5 8\n2 ...
30
0
-1
1,458
612
Replace To Make Regular Bracket Sequence
[ "data structures", "expression parsing", "math" ]
null
null
You are given string *s* consists of opening and closing brackets of four kinds &lt;&gt;, {}, [], (). There are two types of brackets: opening and closing. You can replace any bracket by another of the same type. For example, you can replace &lt; by the bracket {, but you can't replace it by ) or &gt;. The following d...
The only line contains a non empty string *s*, consisting of only opening and closing brackets of four kinds. The length of *s* does not exceed 106.
If it's impossible to get RBS from *s* print Impossible. Otherwise print the least number of replaces needed to get RBS from *s*.
[ "[&lt;}){}\n", "{()}[]\n", "]]\n" ]
[ "2", "0", "Impossible" ]
none
[ { "input": "[<}){}", "output": "2" }, { "input": "{()}[]", "output": "0" }, { "input": "]]", "output": "Impossible" }, { "input": ">", "output": "Impossible" }, { "input": "{}", "output": "0" }, { "input": "{}", "output": "0" }, { "input": ...
77
7,065,600
0
1,459
626
Cards
[ "constructive algorithms", "dp", "math" ]
null
null
Catherine has a deck of *n* cards, each of which is either red, green, or blue. As long as there are at least two cards left, she can do one of two actions: - take any two (not necessarily adjacent) cards with different colors and exchange them for a new card of the third color; - take any two (not necessarily adja...
The first line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=200) — the total number of cards. The next line contains a string *s* of length *n* — the colors of the cards. *s* contains only the characters 'B', 'G', and 'R', representing blue, green, and red, respectively.
Print a single string of up to three characters — the possible colors of the final card (using the same symbols as the input) in alphabetical order.
[ "2\nRB\n", "3\nGRG\n", "5\nBBBBB\n" ]
[ "G\n", "BR\n", "B\n" ]
In the first sample, Catherine has one red card and one blue card, which she must exchange for a green card. In the second sample, Catherine has two green cards and one red card. She has two options: she can exchange the two green cards for a green card, then exchange the new green card and the red card for a blue car...
[ { "input": "2\nRB", "output": "G" }, { "input": "3\nGRG", "output": "BR" }, { "input": "5\nBBBBB", "output": "B" }, { "input": "1\nR", "output": "R" }, { "input": "200\nBBRGRRBBRGGGBGBGBGRRGRGRGRBGRGRRBBGRGBGRRGRRRGGBBRGBGBGBRBBBBBBBGGBRGGRRRGGRGBGBGGBRRRRBRRRBRBB...
62
0
0
1,464
0
none
[ "none" ]
null
null
An atom of element X can exist in *n* distinct states with energies *E*1<=&lt;<=*E*2<=&lt;<=...<=&lt;<=*E**n*. Arkady wants to build a laser on this element, using a three-level scheme. Here is a simplified description of the scheme. Three distinct states *i*, *j* and *k* are selected, where *i*<=&lt;<=*j*<=&lt;<=*k*...
The first line contains two integers *n* and *U* (3<=≤<=*n*<=≤<=105, 1<=≤<=*U*<=≤<=109) — the number of states and the maximum possible difference between *E**k* and *E**i*. The second line contains a sequence of integers *E*1,<=*E*2,<=...,<=*E**n* (1<=≤<=*E*1<=&lt;<=*E*2...<=&lt;<=*E**n*<=≤<=109). It is guaranteed th...
If it is not possible to choose three states that satisfy all constraints, print -1. Otherwise, print one real number η — the maximum possible energy conversion efficiency. Your answer is considered correct its absolute or relative error does not exceed 10<=-<=9. Formally, let your answer be *a*, and the jury's answe...
[ "4 4\n1 3 5 7\n", "10 8\n10 13 15 16 17 19 20 22 24 25\n", "3 1\n2 5 10\n" ]
[ "0.5\n", "0.875\n", "-1\n" ]
In the first example choose states 1, 2 and 3, so that the energy conversion efficiency becomes equal to <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/147ae7a830722917b0aa37d064df8eb74cfefb97.png" style="max-width: 100.0%;max-height: 100.0%;"/>. In the second example choose states 4, 5 a...
[ { "input": "4 4\n1 3 5 7", "output": "0.5" }, { "input": "10 8\n10 13 15 16 17 19 20 22 24 25", "output": "0.875" }, { "input": "3 1\n2 5 10", "output": "-1" }, { "input": "5 3\n4 6 8 9 10", "output": "0.5" }, { "input": "10 128\n110 121 140 158 174 188 251 271 27...
93
7,065,600
0
1,467
127
Canvas Frames
[ "implementation" ]
null
null
Nicholas, a painter is going to paint several new canvases. Nicholas is sure that the canvases will turn out so great that each one will need framing and being hung on the wall. Frames are what Nicholas decided to begin with. Nicholas has *n* sticks whose lengths equal *a*1,<=*a*2,<=... *a**n*. Nicholas does not want...
The first line contains an integer *n* (1<=≤<=*n*<=≤<=100) — the number of sticks. The second line contains *n* space-separated integers. The *i*-th integer equals the length of the *i*-th stick *a**i* (1<=≤<=*a**i*<=≤<=100).
Print the single number — the maximum number of frames Nicholas can make for his future canvases.
[ "5\n2 4 3 2 3\n", "13\n2 2 4 4 4 4 6 6 6 7 7 9 9\n", "4\n3 3 3 5\n" ]
[ "1", "3", "0" ]
none
[ { "input": "5\n2 4 3 2 3", "output": "1" }, { "input": "13\n2 2 4 4 4 4 6 6 6 7 7 9 9", "output": "3" }, { "input": "4\n3 3 3 5", "output": "0" }, { "input": "2\n3 5", "output": "0" }, { "input": "9\n1 2 3 4 5 6 7 8 9", "output": "0" }, { "input": "14\...
62
0
3
1,468
633
Spy Syndrome 2
[ "data structures", "dp", "hashing", "implementation", "sortings", "string suffix structures", "strings" ]
null
null
After observing the results of Spy Syndrome, Yash realised the errors of his ways. He now believes that a super spy such as Siddhant can't use a cipher as basic and ancient as Caesar cipher. After many weeks of observation of Siddhant’s sentences, Yash determined a new cipher technique. For a given sentence, the ciphe...
The first line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=10<=000) — the length of the ciphered text. The second line consists of *n* lowercase English letters — the ciphered text *t*. The third line contains a single integer *m* (1<=≤<=*m*<=≤<=100<=000) — the number of words which will be considered wh...
Print one line — the original sentence. It is guaranteed that at least one solution exists. If there are multiple solutions, you may output any of those.
[ "30\nariksihsidlihcdnaehsetahgnisol\n10\nKira\nhates\nis\nhe\nlosing\ndeath\nchildish\nL\nand\nNote\n", "12\niherehtolleh\n5\nHI\nHo\nthere\nHeLLo\nhello\n" ]
[ "Kira is childish and he hates losing \n", "HI there HeLLo \n" ]
In sample case 2 there may be multiple accepted outputs, "HI there HeLLo" and "HI there hello" you may output any of them.
[ { "input": "30\nariksihsidlihcdnaehsetahgnisol\n10\nKira\nhates\nis\nhe\nlosing\ndeath\nchildish\nL\nand\nNote", "output": "Kira is childish and he hates losing " }, { "input": "12\niherehtolleh\n5\nHI\nHo\nthere\nHeLLo\nhello", "output": "HI there HeLLo " }, { "input": "71\nbaaaaaaaaaaa...
93
0
0
1,469
770
Maximize Sum of Digits
[ "*special", "implementation", "math" ]
null
null
Anton has the integer *x*. He is interested what positive integer, which doesn't exceed *x*, has the maximum sum of digits. Your task is to help Anton and to find the integer that interests him. If there are several such integers, determine the biggest of them.
The first line contains the positive integer *x* (1<=≤<=*x*<=≤<=1018) — the integer which Anton has.
Print the positive integer which doesn't exceed *x* and has the maximum sum of digits. If there are several such integers, print the biggest of them. Printed integer must not contain leading zeros.
[ "100\n", "48\n", "521\n" ]
[ "99\n", "48\n", "499\n" ]
none
[ { "input": "100", "output": "99" }, { "input": "48", "output": "48" }, { "input": "521", "output": "499" }, { "input": "1", "output": "1" }, { "input": "2", "output": "2" }, { "input": "3", "output": "3" }, { "input": "39188", "output":...
1,000
0
0
1,473
911
Tree Destruction
[ "constructive algorithms", "dfs and similar", "graphs", "greedy", "trees" ]
null
null
You are given an unweighted tree with *n* vertices. Then *n*<=-<=1 following operations are applied to the tree. A single operation consists of the following steps: 1. choose two leaves; 1. add the length of the simple path between them to the answer; 1. remove one of the chosen leaves from the tree. Initial answ...
The first line contains one integer number *n* (2<=≤<=*n*<=≤<=2·105) — the number of vertices in the tree. Next *n*<=-<=1 lines describe the edges of the tree in form *a**i*,<=*b**i* (1<=≤<=*a**i*, *b**i*<=≤<=*n*, *a**i*<=≠<=*b**i*). It is guaranteed that given graph is a tree.
In the first line print one integer number — maximal possible answer. In the next *n*<=-<=1 lines print the operations in order of their applying in format *a**i*,<=*b**i*,<=*c**i*, where *a**i*,<=*b**i* — pair of the leaves that are chosen in the current operation (1<=≤<=*a**i*, *b**i*<=≤<=*n*), *c**i* (1<=≤<=*c**i*...
[ "3\n1 2\n1 3\n", "5\n1 2\n1 3\n2 4\n2 5\n" ]
[ "3\n2 3 3\n2 1 1\n", "9\n3 5 5\n4 3 3\n4 1 1\n4 2 2\n" ]
none
[ { "input": "3\n1 2\n1 3", "output": "3\n2 3 3\n2 1 1" }, { "input": "5\n1 2\n1 3\n2 4\n2 5", "output": "9\n3 5 5\n4 3 3\n4 1 1\n4 2 2" }, { "input": "2\n1 2", "output": "1\n2 1 1" }, { "input": "4\n1 3\n1 4\n1 2", "output": "5\n3 4 4\n2 3 3\n2 1 1" }, { "input": "...
46
0
0
1,476
747
Mammoth's Genome Decoding
[ "implementation", "strings" ]
null
null
The process of mammoth's genome decoding in Berland comes to its end! One of the few remaining tasks is to restore unrecognized nucleotides in a found chain *s*. Each nucleotide is coded with a capital letter of English alphabet: 'A', 'C', 'G' or 'T'. Unrecognized nucleotides are coded by a question mark '?'. Thus, *s...
The first line contains the integer *n* (4<=≤<=*n*<=≤<=255) — the length of the genome. The second line contains the string *s* of length *n* — the coded genome. It consists of characters 'A', 'C', 'G', 'T' and '?'.
If it is possible to decode the genome, print it. If there are multiple answer, print any of them. If it is not possible, print three equals signs in a row: "===" (without quotes).
[ "8\nAG?C??CT\n", "4\nAGCT\n", "6\n????G?\n", "4\nAA??\n" ]
[ "AGACGTCT\n", "AGCT\n", "===\n", "===\n" ]
In the first example you can replace the first question mark with the letter 'A', the second question mark with the letter 'G', the third question mark with the letter 'T', then each nucleotide in the genome would be presented twice. In the second example the genome is already decoded correctly and each nucleotide is ...
[ { "input": "8\nAG?C??CT", "output": "AGACGTCT" }, { "input": "4\nAGCT", "output": "AGCT" }, { "input": "6\n????G?", "output": "===" }, { "input": "4\nAA??", "output": "===" }, { "input": "4\n????", "output": "ACGT" }, { "input": "252\n???????GCG??T??TT...
92
2,252,800
-1
1,480
785
Anton and Fairy Tale
[ "binary search", "math" ]
null
null
Anton likes to listen to fairy tales, especially when Danik, Anton's best friend, tells them. Right now Danik tells Anton a fairy tale: "Once upon a time, there lived an emperor. He was very rich and had much grain. One day he ordered to build a huge barn to put there all his grain. Best builders were building that ba...
The only line of the input contains two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=1018) — the capacity of the barn and the number of grains that are brought every day.
Output one integer — the number of the day when the barn will become empty for the first time. Days are numbered starting with one.
[ "5 2\n", "8 1\n" ]
[ "4\n", "5\n" ]
In the first sample the capacity of the barn is five grains and two grains are brought every day. The following happens: - At the beginning of the first day grain is brought to the barn. It's full, so nothing happens. - At the end of the first day one sparrow comes and eats one grain, so 5 - 1 = 4 grains remain. - ...
[ { "input": "5 2", "output": "4" }, { "input": "8 1", "output": "5" }, { "input": "32 5", "output": "12" }, { "input": "1024 1024", "output": "1024" }, { "input": "58044 52909", "output": "53010" }, { "input": "996478063 658866858", "output": "65889...
514
25,600,000
0
1,482
441
Valera and Antique Items
[ "implementation" ]
null
null
Valera is a collector. Once he wanted to expand his collection with exactly one antique item. Valera knows *n* sellers of antiques, the *i*-th of them auctioned *k**i* items. Currently the auction price of the *j*-th object of the *i*-th seller is *s**ij*. Valera gets on well with each of the *n* sellers. He is perfec...
The first line contains two space-separated integers *n*,<=*v* (1<=≤<=*n*<=≤<=50; 104<=≤<=*v*<=≤<=106) — the number of sellers and the units of money the Valera has. Then *n* lines follow. The *i*-th line first contains integer *k**i* (1<=≤<=*k**i*<=≤<=50) the number of items of the *i*-th seller. Then go *k**i* space...
In the first line, print integer *p* — the number of sellers with who Valera can make a deal. In the second line print *p* space-separated integers *q*1,<=*q*2,<=...,<=*q**p* (1<=≤<=*q**i*<=≤<=*n*) — the numbers of the sellers with who Valera can make a deal. Print the numbers of the sellers in the increasing order.
[ "3 50000\n1 40000\n2 20000 60000\n3 10000 70000 190000\n", "3 50000\n1 50000\n3 100000 120000 110000\n3 120000 110000 120000\n" ]
[ "3\n1 2 3\n", "0\n\n" ]
In the first sample Valera can bargain with each of the sellers. He can outbid the following items: a 40000 item from the first seller, a 20000 item from the second seller, and a 10000 item from the third seller. In the second sample Valera can not make a deal with any of the sellers, as the prices of all items in the...
[ { "input": "3 50000\n1 40000\n2 20000 60000\n3 10000 70000 190000", "output": "3\n1 2 3" }, { "input": "3 50000\n1 50000\n3 100000 120000 110000\n3 120000 110000 120000", "output": "0" }, { "input": "2 100001\n1 895737\n1 541571", "output": "0" }, { "input": "1 1000000\n1 100...
109
0
3
1,485
0
none
[ "none" ]
null
null
Santa Claus has Robot which lives on the infinite grid and can move along its lines. He can also, having a sequence of *m* points *p*1,<=*p*2,<=...,<=*p**m* with integer coordinates, do the following: denote its initial location by *p*0. First, the robot will move from *p*0 to *p*1 along one of the shortest paths betwe...
The first line of input contains the only positive integer *n* (1<=≤<=*n*<=≤<=2·105) which equals the number of unit segments the robot traveled. The second line contains the movements protocol, which consists of *n* letters, each being equal either L, or R, or U, or D. *k*-th letter stands for the direction which Robo...
The only line of input should contain the minimum possible length of the sequence.
[ "4\nRURD\n", "6\nRRULDD\n", "26\nRRRULURURUULULLLDLDDRDRDLD\n", "3\nRLL\n", "4\nLRLR\n" ]
[ "2\n", "2\n", "7\n", "2\n", "4\n" ]
The illustrations to the first three tests are given below. <img class="tex-graphics" src="https://espresso.codeforces.com/832fb8f97a482be815e0f87edde26c9791a0d330.png" style="max-width: 100.0%;max-height: 100.0%;"/> <img class="tex-graphics" src="https://espresso.codeforces.com/119a8ba68772b2c2bf76f2acdc58027f6c5cde1...
[ { "input": "4\nRURD", "output": "2" }, { "input": "6\nRRULDD", "output": "2" }, { "input": "26\nRRRULURURUULULLLDLDDRDRDLD", "output": "7" }, { "input": "3\nRLL", "output": "2" }, { "input": "4\nLRLR", "output": "4" }, { "input": "5\nLRDLR", "outpu...
2,000
5,222,400
0
1,489
864
Fair Game
[ "implementation", "sortings" ]
null
null
Petya and Vasya decided to play a game. They have *n* cards (*n* is an even number). A single integer is written on each card. Before the game Petya will choose an integer and after that Vasya will choose another integer (different from the number that Petya chose). During the game each player takes all the cards with...
The first line contains a single integer *n* (2<=≤<=*n*<=≤<=100) — number of cards. It is guaranteed that *n* is an even number. The following *n* lines contain a sequence of integers *a*1,<=*a*2,<=...,<=*a**n* (one integer per line, 1<=≤<=*a**i*<=≤<=100) — numbers written on the *n* cards.
If it is impossible for Petya and Vasya to choose numbers in such a way that the game will be fair, print "NO" (without quotes) in the first line. In this case you should not print anything more. In the other case print "YES" (without quotes) in the first line. In the second line print two distinct integers — number t...
[ "4\n11\n27\n27\n11\n", "2\n6\n6\n", "6\n10\n20\n30\n20\n10\n20\n", "6\n1\n1\n2\n2\n3\n3\n" ]
[ "YES\n11 27\n", "NO\n", "NO\n", "NO\n" ]
In the first example the game will be fair if, for example, Petya chooses number 11, and Vasya chooses number 27. Then the will take all cards — Petya will take cards 1 and 4, and Vasya will take cards 2 and 3. Thus, each of them will take exactly two cards. In the second example fair game is impossible because the nu...
[ { "input": "4\n11\n27\n27\n11", "output": "YES\n11 27" }, { "input": "2\n6\n6", "output": "NO" }, { "input": "6\n10\n20\n30\n20\n10\n20", "output": "NO" }, { "input": "6\n1\n1\n2\n2\n3\n3", "output": "NO" }, { "input": "2\n1\n100", "output": "YES\n1 100" }, ...
46
0
0
1,492
574
Bear and Elections
[ "greedy", "implementation" ]
null
null
Limak is a grizzly bear who desires power and adoration. He wants to win in upcoming elections and rule over the Bearland. There are *n* candidates, including Limak. We know how many citizens are going to vote for each candidate. Now *i*-th candidate would get *a**i* votes. Limak is candidate number 1. To win in elect...
The first line contains single integer *n* (2<=≤<=*n*<=≤<=100) - number of candidates. The second line contains *n* space-separated integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=1000) - number of votes for each candidate. Limak is candidate number 1. Note that after bribing number of votes for some candidate ...
Print the minimum number of citizens Limak must bribe to have strictly more votes than any other candidate.
[ "5\n5 1 11 2 8\n", "4\n1 8 8 8\n", "2\n7 6\n" ]
[ "4\n", "6\n", "0\n" ]
In the first sample Limak has 5 votes. One of the ways to achieve victory is to bribe 4 citizens who want to vote for the third candidate. Then numbers of votes would be 9, 1, 7, 2, 8 (Limak would have 9 votes). Alternatively, Limak could steal only 3 votes from the third candidate and 1 vote from the second candidate ...
[ { "input": "5\n5 1 11 2 8", "output": "4" }, { "input": "4\n1 8 8 8", "output": "6" }, { "input": "2\n7 6", "output": "0" }, { "input": "2\n1 1", "output": "1" }, { "input": "10\n100 200 57 99 1 1000 200 200 200 500", "output": "451" }, { "input": "16\...
62
1,740,800
3
1,494
192
Funky Numbers
[ "binary search", "brute force", "implementation" ]
null
null
As you very well know, this year's funkiest numbers are so called triangular numbers (that is, integers that are representable as , where *k* is some positive integer), and the coolest numbers are those that are representable as a sum of two triangular numbers. A well-known hipster Andrew adores everything funky and c...
The first input line contains an integer *n* (1<=≤<=*n*<=≤<=109).
Print "YES" (without the quotes), if *n* can be represented as a sum of two triangular numbers, otherwise print "NO" (without the quotes).
[ "256\n", "512\n" ]
[ "YES\n", "NO\n" ]
In the first sample number <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/92095692c6ea93e9e3b837a0408ba7543549d5b2.png" style="max-width: 100.0%;max-height: 100.0%;"/>. In the second sample number 512 can not be represented as a sum of two triangular numbers.
[ { "input": "256", "output": "YES" }, { "input": "512", "output": "NO" }, { "input": "80", "output": "NO" }, { "input": "828", "output": "YES" }, { "input": "6035", "output": "NO" }, { "input": "39210", "output": "YES" }, { "input": "79712",...
62
0
0
1,497
792
Counting-out Rhyme
[ "implementation" ]
null
null
*n* children are standing in a circle and playing the counting-out game. Children are numbered clockwise from 1 to *n*. In the beginning, the first child is considered the leader. The game is played in *k* steps. In the *i*-th step the leader counts out *a**i* people in clockwise order, starting from the next person. T...
The first line contains two integer numbers *n* and *k* (2<=≤<=*n*<=≤<=100, 1<=≤<=*k*<=≤<=*n*<=-<=1). The next line contains *k* integer numbers *a*1,<=*a*2,<=...,<=*a**k* (1<=≤<=*a**i*<=≤<=109).
Print *k* numbers, the *i*-th one corresponds to the number of child to be eliminated at the *i*-th step.
[ "7 5\n10 4 11 4 1\n", "3 2\n2 5\n" ]
[ "4 2 5 6 1 \n", "3 2 \n" ]
Let's consider first example: - In the first step child 4 is eliminated, child 5 becomes the leader. - In the second step child 2 is eliminated, child 3 becomes the leader. - In the third step child 5 is eliminated, child 6 becomes the leader. - In the fourth step child 6 is eliminated, child 7 becomes the leader...
[ { "input": "7 5\n10 4 11 4 1", "output": "4 2 5 6 1 " }, { "input": "3 2\n2 5", "output": "3 2 " }, { "input": "2 1\n1", "output": "2 " }, { "input": "2 1\n2", "output": "1 " }, { "input": "2 1\n3", "output": "2 " }, { "input": "10 7\n5 10 4 3 8 10 6",...
62
0
3
1,499
412
Poster
[ "greedy", "implementation" ]
null
null
The R1 company has recently bought a high rise building in the centre of Moscow for its main office. It's time to decorate the new office, and the first thing to do is to write the company's slogan above the main entrance to the building. The slogan of the company consists of *n* characters, so the decorators hung a l...
The first line contains two integers, *n* and *k* (1<=≤<=*k*<=≤<=*n*<=≤<=100) — the number of characters in the slogan and the initial position of the ladder, correspondingly. The next line contains the slogan as *n* characters written without spaces. Each character of the slogan is either a large English letter, or di...
In *t* lines, print the actions the programmers need to make. In the *i*-th line print: - "LEFT" (without the quotes), if the *i*-th action was "move the ladder to the left"; - "RIGHT" (without the quotes), if the *i*-th action was "move the ladder to the right"; - "PRINT *x*" (without the quotes), if the *i*-th ac...
[ "2 2\nR1\n", "2 1\nR1\n", "6 4\nGO?GO!\n" ]
[ "PRINT 1\nLEFT\nPRINT R\n", "PRINT R\nRIGHT\nPRINT 1\n", "RIGHT\nRIGHT\nPRINT !\nLEFT\nPRINT O\nLEFT\nPRINT G\nLEFT\nPRINT ?\nLEFT\nPRINT O\nLEFT\nPRINT G\n" ]
Note that the ladder cannot be shifted by less than one meter. The ladder can only stand in front of some square of the poster. For example, you cannot shift a ladder by half a meter and position it between two squares. Then go up and paint the first character and the second character.
[ { "input": "2 2\nR1", "output": "PRINT 1\nLEFT\nPRINT R" }, { "input": "2 1\nR1", "output": "PRINT R\nRIGHT\nPRINT 1" }, { "input": "6 4\nGO?GO!", "output": "RIGHT\nRIGHT\nPRINT !\nLEFT\nPRINT O\nLEFT\nPRINT G\nLEFT\nPRINT ?\nLEFT\nPRINT O\nLEFT\nPRINT G" }, { "input": "7 3\n...
62
0
3
1,500
690
Brain Network (easy)
[]
null
null
One particularly well-known fact about zombies is that they move and think terribly slowly. While we still don't know why their movements are so sluggish, the problem of laggy thinking has been recently resolved. It turns out that the reason is not (as previously suspected) any kind of brain defect – it's the opposite!...
The first line of the input contains two space-separated integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=1000) denoting the number of brains (which are conveniently numbered from 1 to *n*) and the number of brain connectors in the nervous system, respectively. In the next *m* lines, descriptions of brain connectors follow. E...
The output consists of one line, containing either yes or no depending on whether the nervous system is valid.
[ "4 4\n1 2\n2 3\n3 1\n4 1\n", "6 5\n1 2\n2 3\n3 4\n4 5\n3 6\n" ]
[ "no\n", "yes\n" ]
none
[ { "input": "4 4\n1 2\n2 3\n3 1\n4 1", "output": "no" }, { "input": "6 5\n1 2\n2 3\n3 4\n4 5\n3 6", "output": "yes" }, { "input": "2 1\n1 2", "output": "yes" }, { "input": "3 3\n2 1\n1 3\n3 2", "output": "no" }, { "input": "3 2\n1 2\n2 3", "output": "yes" }, ...
109
0
0
1,501
182
Vasya's Calendar
[ "implementation" ]
null
null
Vasya lives in a strange world. The year has *n* months and the *i*-th month has *a**i* days. Vasya got a New Year present — the clock that shows not only the time, but also the date. The clock's face can display any number from 1 to *d*. It is guaranteed that *a**i*<=≤<=*d* for all *i* from 1 to *n*. The clock does n...
The first line contains the single number *d* — the maximum number of the day that Vasya's clock can show (1<=≤<=*d*<=≤<=106). The second line contains a single integer *n* — the number of months in the year (1<=≤<=*n*<=≤<=2000). The third line contains *n* space-separated integers: *a**i* (1<=≤<=*a**i*<=≤<=*d*) — th...
Print a single number — the number of times Vasya manually increased the day number by one throughout the last year.
[ "4\n2\n2 2\n", "5\n3\n3 4 3\n", "31\n12\n31 28 31 30 31 30 31 31 30 31 30 31\n" ]
[ "2\n", "3\n", "7\n" ]
In the first sample the situation is like this: - Day 1. Month 1. The clock shows 1. Vasya changes nothing. - Day 2. Month 1. The clock shows 2. Vasya changes nothing. - Day 1. Month 2. The clock shows 3. Vasya manually increases the day number by 1. After that the clock shows 4. Vasya increases the day number by ...
[ { "input": "4\n2\n2 2", "output": "2" }, { "input": "5\n3\n3 4 3", "output": "3" }, { "input": "31\n12\n31 28 31 30 31 30 31 31 30 31 30 31", "output": "7" }, { "input": "1\n1\n1", "output": "0" }, { "input": "1\n2\n1 1", "output": "0" }, { "input": "2...
404
2,355,200
-1
1,505
266
Queue at the School
[ "constructive algorithms", "graph matchings", "implementation", "shortest paths" ]
null
null
During the break the schoolchildren, boys and girls, formed a queue of *n* people in the canteen. Initially the children stood in the order they entered the canteen. However, after a while the boys started feeling awkward for standing in front of the girls in the queue and they started letting the girls move forward ea...
The first line contains two integers *n* and *t* (1<=≤<=*n*,<=*t*<=≤<=50), which represent the number of children in the queue and the time after which the queue will transform into the arrangement you need to find. The next line contains string *s*, which represents the schoolchildren's initial arrangement. If the *...
Print string *a*, which describes the arrangement after *t* seconds. If the *i*-th position has a boy after the needed time, then the *i*-th character *a* must equal "B", otherwise it must equal "G".
[ "5 1\nBGGBG\n", "5 2\nBGGBG\n", "4 1\nGGGB\n" ]
[ "GBGGB\n", "GGBGB\n", "GGGB\n" ]
none
[ { "input": "5 1\nBGGBG", "output": "GBGGB" }, { "input": "5 2\nBGGBG", "output": "GGBGB" }, { "input": "4 1\nGGGB", "output": "GGGB" }, { "input": "2 1\nBB", "output": "BB" }, { "input": "2 1\nBG", "output": "GB" }, { "input": "6 2\nBBGBBG", "outpu...
92
0
3
1,508
1
Spreadsheet
[ "implementation", "math" ]
B. Spreadsheets
10
64
In the popular spreadsheets systems (for example, in Excel) the following numeration of columns is used. The first column has number A, the second — number B, etc. till column 26 that is marked by Z. Then there are two-letter numbers: column 27 has number AA, 28 — AB, column 52 is marked by AZ. After ZZ there follow th...
The first line of the input contains integer number *n* (1<=≤<=*n*<=≤<=105), the number of coordinates in the test. Then there follow *n* lines, each of them contains coordinates. All the coordinates are correct, there are no cells with the column and/or the row numbers larger than 106 .
Write *n* lines, each line should contain a cell coordinates in the other numeration system.
[ "2\nR23C55\nBC23\n" ]
[ "BC23\nR23C55\n" ]
none
[ { "input": "2\nR23C55\nBC23", "output": "BC23\nR23C55" }, { "input": "1\nA1", "output": "R1C1" }, { "input": "5\nR8C3\nD1\nR7C2\nR8C9\nR8C9", "output": "C8\nR1C4\nB7\nI8\nI8" }, { "input": "4\nR4C25\nR90C35\nAP55\nX83", "output": "Y4\nAI90\nR55C42\nR83C24" }, { "i...
92
0
0
1,509
427
Prison Transfer
[ "data structures", "implementation" ]
null
null
The prison of your city has *n* prisoners. As the prison can't accommodate all of them, the city mayor has decided to transfer *c* of the prisoners to a prison located in another city. For this reason, he made the *n* prisoners to stand in a line, with a number written on their chests. The number is the severity of th...
The first line of input will contain three space separated integers *n* (1<=≤<=*n*<=≤<=2·105), *t* (0<=≤<=*t*<=≤<=109) and *c* (1<=≤<=*c*<=≤<=*n*). The next line will contain *n* space separated integers, the *i**th* integer is the severity *i**th* prisoner's crime. The value of crime severities will be non-negative an...
Print a single integer — the number of ways you can choose the *c* prisoners.
[ "4 3 3\n2 3 1 1\n", "1 1 1\n2\n", "11 4 2\n2 2 0 7 3 2 2 4 9 1 4\n" ]
[ "2\n", "0\n", "6\n" ]
none
[ { "input": "4 3 3\n2 3 1 1", "output": "2" }, { "input": "1 1 1\n2", "output": "0" }, { "input": "11 4 2\n2 2 0 7 3 2 2 4 9 1 4", "output": "6" }, { "input": "57 2 10\n7 5 2 7 4 1 0 5 2 9 2 9 8 6 6 5 9 6 8 1 0 1 0 3 2 6 5 2 8 8 8 8 0 9 4 3 6 6 2 4 5 1 2 0 1 7 1 1 5 4 5 0 7 5 ...
139
25,600,000
-1
1,515
225
Barcode
[ "dp", "matrices" ]
null
null
You've got an *n*<=×<=*m* pixel picture. Each pixel can be white or black. Your task is to change the colors of as few pixels as possible to obtain a barcode picture. A picture is a barcode if the following conditions are fulfilled: - All pixels in each column are of the same color. - The width of each monochrome ...
The first line contains four space-separated integers *n*, *m*, *x* and *y* (1<=≤<=*n*,<=*m*,<=*x*,<=*y*<=≤<=1000; *x*<=≤<=*y*). Then follow *n* lines, describing the original image. Each of these lines contains exactly *m* characters. Character "." represents a white pixel and "#" represents a black pixel. The pictur...
In the first line print the minimum number of pixels to repaint. It is guaranteed that the answer exists.
[ "6 5 1 2\n##.#.\n.###.\n###..\n#...#\n.##.#\n###..\n", "2 5 1 1\n#####\n.....\n" ]
[ "11\n", "5\n" ]
In the first test sample the picture after changing some colors can looks as follows: In the second test sample the picture after changing some colors can looks as follows:
[ { "input": "6 5 1 2\n##.#.\n.###.\n###..\n#...#\n.##.#\n###..", "output": "11" }, { "input": "10 5 3 7\n.####\n###..\n##.##\n#..#.\n.#...\n#.##.\n.##..\n.#.##\n#.#..\n.#..#", "output": "24" }, { "input": "6 3 1 4\n##.\n#..\n#..\n..#\n.#.\n#.#", "output": "6" }, { "input": "5 ...
154
0
0
1,516
984
Minesweeper
[ "implementation" ]
null
null
One day Alex decided to remember childhood when computers were not too powerful and lots of people played only default games. Alex enjoyed playing Minesweeper that time. He imagined that he saved world from bombs planted by terrorists, but he rarely won. Alex has grown up since then, so he easily wins the most difficu...
The first line contains two integers $n$ and $m$ ($1 \le n, m \le 100$) — the sizes of the field. The next $n$ lines contain the description of the field. Each line contains $m$ characters, each of them is "." (if this cell is empty), "*" (if there is bomb in this cell), or a digit from $1$ to $8$, inclusive.
Print "YES", if the field is valid and "NO" otherwise. You can choose the case (lower or upper) for each letter arbitrarily.
[ "3 3\n111\n1*1\n111\n", "2 4\n*.*.\n1211\n" ]
[ "YES", "NO" ]
In the second example the answer is "NO" because, if the positions of the bombs are preserved, the first line of the field should be *2*1. You can read more about Minesweeper in [Wikipedia's article](https://en.wikipedia.org/wiki/Minesweeper_(video_game)).
[ { "input": "3 3\n111\n1*1\n111", "output": "YES" }, { "input": "2 4\n*.*.\n1211", "output": "NO" }, { "input": "1 10\n.....1*1..", "output": "YES" }, { "input": "1 1\n4", "output": "NO" }, { "input": "10 10\n..........\n...111111.\n..13*21*1.\n.12**2111.\n.1*542.....
31
0
0
1,517
847
Weather Tomorrow
[ "implementation", "math" ]
null
null
Vasya came up with his own weather forecasting method. He knows the information about the average air temperature for each of the last *n* days. Assume that the average air temperature for each day is integral. Vasya believes that if the average temperatures over the last *n* days form an arithmetic progression, where...
The first line contains a single integer *n* (2<=≤<=*n*<=≤<=100) — the number of days for which the average air temperature is known. The second line contains a sequence of integers *t*1,<=*t*2,<=...,<=*t**n* (<=-<=1000<=≤<=*t**i*<=≤<=1000) — where *t**i* is the average temperature in the *i*-th day.
Print the average air temperature in the (*n*<=+<=1)-th day, which Vasya predicts according to his method. Note that the absolute value of the predicted temperature can exceed 1000.
[ "5\n10 5 0 -5 -10\n", "4\n1 1 1 1\n", "3\n5 1 -5\n", "2\n900 1000\n" ]
[ "-15\n", "1\n", "-5\n", "1100\n" ]
In the first example the sequence of the average temperatures is an arithmetic progression where the first term is 10 and each following terms decreases by 5. So the predicted average temperature for the sixth day is  - 10 - 5 =  - 15. In the second example the sequence of the average temperatures is an arithmetic pro...
[ { "input": "5\n10 5 0 -5 -10", "output": "-15" }, { "input": "4\n1 1 1 1", "output": "1" }, { "input": "3\n5 1 -5", "output": "-5" }, { "input": "2\n900 1000", "output": "1100" }, { "input": "2\n1 2", "output": "3" }, { "input": "3\n2 5 8", "output...
46
0
3
1,527
0
none
[ "none" ]
null
null
Asterix, Obelix and their temporary buddies Suffix and Prefix has finally found the Harmony temple. However, its doors were firmly locked and even Obelix had no luck opening them. A little later they found a string *s*, carved on a rock below the temple's gates. Asterix supposed that that's the password that opens the...
You are given the string *s* whose length can vary from 1 to 106 (inclusive), consisting of small Latin letters.
Print the string *t*. If a suitable *t* string does not exist, then print "Just a legend" without the quotes.
[ "fixprefixsuffix\n", "abcdabc\n" ]
[ "fix", "Just a legend" ]
none
[ { "input": "fixprefixsuffix", "output": "fix" }, { "input": "abcdabc", "output": "Just a legend" }, { "input": "qwertyqwertyqwerty", "output": "qwerty" }, { "input": "papapapap", "output": "papap" }, { "input": "aaaaaaaaaa", "output": "aaaaaaaa" }, { "...
124
4,608,000
0
1,529
260
Ancient Prophesy
[ "brute force", "implementation", "strings" ]
null
null
A recently found Ancient Prophesy is believed to contain the exact Apocalypse date. The prophesy is a string that only consists of digits and characters "-". We'll say that some date is mentioned in the Prophesy if there is a substring in the Prophesy that is the date's record in the format "dd-mm-yyyy". We'll say tha...
The first line contains the Prophesy: a non-empty string that only consists of digits and characters "-". The length of the Prophesy doesn't exceed 105 characters.
In a single line print the date of the Apocalypse. It is guaranteed that such date exists and is unique.
[ "777-444---21-12-2013-12-2013-12-2013---444-777\n" ]
[ "13-12-2013" ]
none
[ { "input": "777-444---21-12-2013-12-2013-12-2013---444-777", "output": "13-12-2013" }, { "input": "30-12-201429-15-208830-12-2014", "output": "30-12-2014" }, { "input": "14-08-201314-08-201314-08-201381-16-20172406414-08-201314-08-201314-08-20134237014-08-201314-08-2013", "output": "...
546
1,536,000
-1
1,531
656
Da Vinci Powers
[ "*special" ]
null
null
The input contains a single integer *a* (0<=≤<=*a*<=≤<=35). Output a single integer.
The input contains a single integer *a* (0<=≤<=*a*<=≤<=35).
Output a single integer.
[ "3\n", "10\n" ]
[ "8\n", "1024\n" ]
none
[ { "input": "3", "output": "8" }, { "input": "10", "output": "1024" }, { "input": "35", "output": "33940307968" }, { "input": "0", "output": "1" }, { "input": "1", "output": "2" }, { "input": "2", "output": "4" }, { "input": "4", "output...
62
0
3
1,532
757
Gotta Catch Em' All!
[ "implementation" ]
null
null
Bash wants to become a Pokemon master one day. Although he liked a lot of Pokemon, he has always been fascinated by Bulbasaur the most. Soon, things started getting serious and his fascination turned into an obsession. Since he is too young to go out and catch Bulbasaur, he came up with his own way of catching a Bulbas...
Input contains a single line containing a string *s* (1<=<=≤<=<=|*s*|<=<=≤<=<=105) — the text on the front page of the newspaper without spaces and punctuation marks. |*s*| is the length of the string *s*. The string *s* contains lowercase and uppercase English letters, i.e. .
Output a single integer, the answer to the problem.
[ "Bulbbasaur\n", "F\n", "aBddulbasaurrgndgbualdBdsagaurrgndbb\n" ]
[ "1\n", "0\n", "2\n" ]
In the first case, you could pick: Bulbbasaur. In the second case, there is no way to pick even a single Bulbasaur. In the third case, you can rearrange the string to BulbasaurBulbasauraddrgndgddgargndbb to get two words "Bulbasaur".
[ { "input": "Bulbbasaur", "output": "1" }, { "input": "F", "output": "0" }, { "input": "aBddulbasaurrgndgbualdBdsagaurrgndbb", "output": "2" }, { "input": "BBBBBBBBBBbbbbbbbbbbuuuuuuuuuullllllllllssssssssssaaaaaaaaaarrrrrrrrrr", "output": "5" }, { "input": "BBBBBBB...
62
0
0
1,533
918
Radio Station
[ "implementation", "strings" ]
null
null
As the guys fried the radio station facilities, the school principal gave them tasks as a punishment. Dustin's task was to add comments to nginx configuration for school's website. The school has *n* servers. Each server has a name and an ip (names aren't necessarily unique, but ips are). Dustin knows the ip and name o...
The first line of input contains two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=1000). The next *n* lines contain the names and ips of the servers. Each line contains a string name, name of the server and a string ip, ip of the server, separated by space (1<=≤<=|*name*|<=≤<=10, *name* only consists of English lowercase...
Print *m* lines, the commands in the configuration file after Dustin did his task.
[ "2 2\nmain 192.168.0.2\nreplica 192.168.0.1\nblock 192.168.0.1;\nproxy 192.168.0.2;\n", "3 5\ngoogle 8.8.8.8\ncodeforces 212.193.33.27\nserver 138.197.64.57\nredirect 138.197.64.57;\nblock 8.8.8.8;\ncf 212.193.33.27;\nunblock 8.8.8.8;\ncheck 138.197.64.57;\n" ]
[ "block 192.168.0.1; #replica\nproxy 192.168.0.2; #main\n", "redirect 138.197.64.57; #server\nblock 8.8.8.8; #google\ncf 212.193.33.27; #codeforces\nunblock 8.8.8.8; #google\ncheck 138.197.64.57; #server\n" ]
none
[ { "input": "2 2\nmain 192.168.0.2\nreplica 192.168.0.1\nblock 192.168.0.1;\nproxy 192.168.0.2;", "output": "block 192.168.0.1; #replica\nproxy 192.168.0.2; #main" }, { "input": "3 5\ngoogle 8.8.8.8\ncodeforces 212.193.33.27\nserver 138.197.64.57\nredirect 138.197.64.57;\nblock 8.8.8.8;\ncf 212.193.3...
46
0
0
1,537
336
Vasily the Bear and Sequence
[ "brute force", "greedy", "implementation", "number theory" ]
null
null
Vasily the bear has got a sequence of positive integers *a*1,<=*a*2,<=...,<=*a**n*. Vasily the Bear wants to write out several numbers on a piece of paper so that the beauty of the numbers he wrote out was maximum. The beauty of the written out numbers *b*1,<=*b*2,<=...,<=*b**k* is such maximum non-negative integer *...
The first line contains integer *n* (1<=≤<=*n*<=≤<=105). The second line contains *n* space-separated integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a*1<=&lt;<=*a*2<=&lt;<=...<=&lt;<=*a**n*<=≤<=109).
In the first line print a single integer *k* (*k*<=&gt;<=0), showing how many numbers to write out. In the second line print *k* integers *b*1,<=*b*2,<=...,<=*b**k* — the numbers to write out. You are allowed to print numbers *b*1,<=*b*2,<=...,<=*b**k* in any order, but all of them must be distinct. If there are multip...
[ "5\n1 2 3 4 5\n", "3\n1 2 4\n" ]
[ "2\n4 5\n", "1\n4\n" ]
none
[ { "input": "5\n1 2 3 4 5", "output": "2\n4 5" }, { "input": "3\n1 2 4", "output": "1\n4" }, { "input": "3\n1 20 22", "output": "2\n20 22" }, { "input": "10\n109070199 215498062 361633800 406156967 452258663 530571268 670482660 704334662 841023955 967424642", "output": "6\...
61
6,963,200
0
1,539
75
Modified GCD
[ "binary search", "number theory" ]
C. Modified GCD
2
256
Well, here is another math class task. In mathematics, GCD is the greatest common divisor, and it's an easy task to calculate the GCD between two positive integers. A common divisor for two positive numbers is a number which both numbers are divisible by. But your teacher wants to give you a harder task, in this task...
The first line contains two integers *a* and *b*, the two integers as described above (1<=≤<=*a*,<=*b*<=≤<=109). The second line contains one integer *n*, the number of queries (1<=≤<=*n*<=≤<=104). Then *n* lines follow, each line contains one query consisting of two integers, *low* and *high* (1<=≤<=*low*<=≤<=*high*<=...
Print *n* lines. The *i*-th of them should contain the result of the *i*-th query in the input. If there is no common divisor in the given range for any query, you should print -1 as a result for this query.
[ "9 27\n3\n1 5\n10 11\n9 11\n" ]
[ "3\n-1\n9\n" ]
none
[ { "input": "9 27\n3\n1 5\n10 11\n9 11", "output": "3\n-1\n9" }, { "input": "48 72\n2\n8 29\n29 37", "output": "24\n-1" }, { "input": "90 100\n10\n51 61\n6 72\n1 84\n33 63\n37 69\n18 21\n9 54\n49 90\n14 87\n37 90", "output": "-1\n10\n10\n-1\n-1\n-1\n10\n-1\n-1\n-1" }, { "input...
592
614,400
3.850856
1,545
839
Arya and Bran
[ "implementation" ]
null
null
Bran and his older sister Arya are from the same house. Bran like candies so much, so Arya is going to give him some Candies. At first, Arya and Bran have 0 Candies. There are *n* days, at the *i*-th day, Arya finds *a**i* candies in a box, that is given by the Many-Faced God. Every day she can give Bran at most 8 of ...
The first line contains two integers *n* and *k* (1<=≤<=*n*<=≤<=100, 1<=≤<=*k*<=≤<=10000). The second line contains *n* integers *a*1,<=*a*2,<=*a*3,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=100).
If it is impossible for Arya to give Bran *k* candies within *n* days, print -1. Otherwise print a single integer — the minimum number of days Arya needs to give Bran *k* candies before the end of the *n*-th day.
[ "2 3\n1 2\n", "3 17\n10 10 10\n", "1 9\n10\n" ]
[ "2", "3", "-1" ]
In the first sample, Arya can give Bran 3 candies in 2 days. In the second sample, Arya can give Bran 17 candies in 3 days, because she can give him at most 8 candies per day. In the third sample, Arya can't give Bran 9 candies, because she can give him at most 8 candies per day and she must give him the candies with...
[ { "input": "2 3\n1 2", "output": "2" }, { "input": "3 17\n10 10 10", "output": "3" }, { "input": "1 9\n10", "output": "-1" }, { "input": "10 70\n6 5 2 3 3 2 1 4 3 2", "output": "-1" }, { "input": "20 140\n40 4 81 40 10 54 34 50 84 60 16 1 90 78 38 93 99 60 81 99",...
202
2,355,200
0
1,546
862
Mahmoud and Ehab and the MEX
[ "greedy", "implementation" ]
null
null
Dr. Evil kidnapped Mahmoud and Ehab in the evil land because of their performance in the Evil Olympiad in Informatics (EOI). He decided to give them some problems to let them go. Dr. Evil is interested in sets, He has a set of *n* integers. Dr. Evil calls a set of integers evil if the MEX of it is exactly *x*. the MEX...
The first line contains two integers *n* and *x* (1<=≤<=*n*<=≤<=100, 0<=≤<=*x*<=≤<=100) — the size of the set Dr. Evil owns, and the desired MEX. The second line contains *n* distinct non-negative integers not exceeding 100 that represent the set.
The only line should contain one integer — the minimal number of operations Dr. Evil should perform.
[ "5 3\n0 4 5 6 7\n", "1 0\n0\n", "5 0\n1 2 3 4 5\n" ]
[ "2\n", "1\n", "0\n" ]
For the first test case Dr. Evil should add 1 and 2 to the set performing 2 operations. For the second test case Dr. Evil should erase 0 from the set. After that, the set becomes empty, so the MEX of it is 0. In the third test case the set is already evil.
[ { "input": "5 3\n0 4 5 6 7", "output": "2" }, { "input": "1 0\n0", "output": "1" }, { "input": "5 0\n1 2 3 4 5", "output": "0" }, { "input": "10 5\n57 1 47 9 93 37 76 70 78 15", "output": "4" }, { "input": "10 5\n99 98 93 97 95 100 92 94 91 96", "output": "5" ...
30
0
0
1,548
371
Vessels
[ "data structures", "dsu", "implementation", "trees" ]
null
null
There is a system of *n* vessels arranged one above the other as shown in the figure below. Assume that the vessels are numbered from 1 to *n*, in the order from the highest to the lowest, the volume of the *i*-th vessel is *a**i* liters. Initially, all the vessels are empty. In some vessels water is poured. All the w...
The first line contains integer *n* — the number of vessels (1<=≤<=*n*<=≤<=2·105). The second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* — the vessels' capacities (1<=≤<=*a**i*<=≤<=109). The vessels' capacities do not necessarily increase from the top vessels to the bottom ones (see the second sample). The t...
For each query, print on a single line the number of liters of water in the corresponding vessel.
[ "2\n5 10\n6\n1 1 4\n2 1\n1 2 5\n1 1 4\n2 1\n2 2\n", "3\n5 10 8\n6\n1 1 12\n2 2\n1 1 6\n1 3 2\n2 2\n2 3\n" ]
[ "4\n5\n8\n", "7\n10\n5\n" ]
none
[ { "input": "2\n5 10\n6\n1 1 4\n2 1\n1 2 5\n1 1 4\n2 1\n2 2", "output": "4\n5\n8" }, { "input": "3\n5 10 8\n6\n1 1 12\n2 2\n1 1 6\n1 3 2\n2 2\n2 3", "output": "7\n10\n5" }, { "input": "10\n71 59 88 55 18 98 38 73 53 58\n20\n1 5 93\n1 7 69\n2 3\n1 1 20\n2 10\n1 6 74\n1 7 100\n1 9 14\n2 3\n...
529
18,739,200
-1
1,553
568
Primes or Palindromes?
[ "brute force", "implementation", "math", "number theory" ]
null
null
Rikhail Mubinchik believes that the current definition of prime numbers is obsolete as they are too complex and unpredictable. A palindromic number is another matter. It is aesthetically pleasing, and it has a number of remarkable properties. Help Rikhail to convince the scientific community in this! Let us remind you...
The input consists of two positive integers *p*, *q*, the numerator and denominator of the fraction that is the value of *A* (, ).
If such maximum number exists, then print it. Otherwise, print "Palindromic tree is better than splay tree" (without the quotes).
[ "1 1\n", "1 42\n", "6 4\n" ]
[ "40\n", "1\n", "172\n" ]
none
[ { "input": "1 1", "output": "40" }, { "input": "1 42", "output": "1" }, { "input": "6 4", "output": "172" }, { "input": "3 1", "output": "2530" }, { "input": "42 1", "output": "1179858" }, { "input": "10000 239", "output": "1168638" }, { "i...
3,000
29,081,600
0
1,555
520
Two Buttons
[ "dfs and similar", "graphs", "greedy", "implementation", "math", "shortest paths" ]
null
null
Vasya has found a strange device. On the front panel of a device there are: a red button, a blue button and a display showing some positive integer. After clicking the red button, device multiplies the displayed number by two. After clicking the blue button, device subtracts one from the number on the display. If at so...
The first and the only line of the input contains two distinct integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=104), separated by a space .
Print a single number — the minimum number of times one needs to push the button required to get the number *m* out of number *n*.
[ "4 6\n", "10 1\n" ]
[ "2\n", "9\n" ]
In the first example you need to push the blue button once, and then push the red button once. In the second example, doubling the number is unnecessary, so we need to push the blue button nine times.
[ { "input": "4 6", "output": "2" }, { "input": "10 1", "output": "9" }, { "input": "1 2", "output": "1" }, { "input": "2 1", "output": "1" }, { "input": "1 3", "output": "3" }, { "input": "3 1", "output": "2" }, { "input": "2 10", "outpu...
61
1,228,800
3
1,556
336
Vasily the Bear and Triangle
[ "implementation", "math" ]
null
null
Vasily the bear has a favorite rectangle, it has one vertex at point (0,<=0), and the opposite vertex at point (*x*,<=*y*). Of course, the sides of Vasya's favorite rectangle are parallel to the coordinate axes. Vasya also loves triangles, if the triangles have one vertex at point *B*<==<=(0,<=0). That's why today he...
The first line contains two integers *x*,<=*y* (<=-<=109<=≤<=*x*,<=*y*<=≤<=109,<=*x*<=≠<=0,<=*y*<=≠<=0).
Print in the single line four integers *x*1,<=*y*1,<=*x*2,<=*y*2 — the coordinates of the required points.
[ "10 5\n", "-10 5\n" ]
[ "0 15 15 0\n", "-15 0 0 15\n" ]
<img class="tex-graphics" src="https://espresso.codeforces.com/a9ea2088c4294ce8f23801562fda36b830df2c3f.png" style="max-width: 100.0%;max-height: 100.0%;"/> Figure to the first sample
[ { "input": "10 5", "output": "0 15 15 0" }, { "input": "-10 5", "output": "-15 0 0 15" }, { "input": "20 -10", "output": "0 -30 30 0" }, { "input": "-10 -1000000000", "output": "-1000000010 0 0 -1000000010" }, { "input": "-1000000000 -1000000000", "output": "-...
186
0
3
1,557
898
Phone Numbers
[ "implementation", "strings" ]
null
null
Vasya has several phone books, in which he recorded the telephone numbers of his friends. Each of his friends can have one or several phone numbers. Vasya decided to organize information about the phone numbers of friends. You will be given *n* strings — all entries from Vasya's phone books. Each entry starts with a f...
First line contains the integer *n* (1<=≤<=*n*<=≤<=20) — number of entries in Vasya's phone books. The following *n* lines are followed by descriptions of the records in the format described in statement. Names of Vasya's friends are non-empty strings whose length does not exceed 10. They consists only of lowercase E...
Print out the ordered information about the phone numbers of Vasya's friends. First output *m* — number of friends that are found in Vasya's phone books. The following *m* lines must contain entries in the following format "name number_of_phone_numbers phone_numbers". Phone numbers should be separated by a space. Each...
[ "2\nivan 1 00123\nmasha 1 00123\n", "3\nkarl 2 612 12\npetr 1 12\nkatya 1 612\n", "4\nivan 3 123 123 456\nivan 2 456 456\nivan 8 789 3 23 6 56 9 89 2\ndasha 2 23 789\n" ]
[ "2\nmasha 1 00123 \nivan 1 00123 \n", "3\nkatya 1 612 \npetr 1 12 \nkarl 1 612 \n", "2\ndasha 2 23 789 \nivan 4 789 123 2 456 \n" ]
none
[ { "input": "2\nivan 1 00123\nmasha 1 00123", "output": "2\nmasha 1 00123 \nivan 1 00123 " }, { "input": "3\nkarl 2 612 12\npetr 1 12\nkatya 1 612", "output": "3\nkatya 1 612 \npetr 1 12 \nkarl 1 612 " }, { "input": "4\nivan 3 123 123 456\nivan 2 456 456\nivan 8 789 3 23 6 56 9 89 2\ndash...
170
307,200
0
1,558
0
none
[ "none" ]
null
null
Theater stage is a rectangular field of size *n*<=×<=*m*. The director gave you the stage's plan which actors will follow. For each cell it is stated in the plan if there would be an actor in this cell or not. You are to place a spotlight on the stage in some good position. The spotlight will project light in one of t...
The first line contains two positive integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=1000) — the number of rows and the number of columns in the plan. The next *n* lines contain *m* integers, 0 or 1 each — the description of the plan. Integer 1, means there will be an actor in the corresponding cell, while 0 means the cell ...
Print one integer — the number of good positions for placing the spotlight.
[ "2 4\n0 1 0 0\n1 0 1 0\n", "4 4\n0 0 0 0\n1 0 0 1\n0 1 1 0\n0 1 0 0\n" ]
[ "9\n", "20\n" ]
In the first example the following positions are good: 1. the (1, 1) cell and right direction; 1. the (1, 1) cell and down direction; 1. the (1, 3) cell and left direction; 1. the (1, 3) cell and down direction; 1. the (1, 4) cell and left direction; 1. the (2, 2) cell and left direction; 1. the (2, 2) cell and...
[ { "input": "2 4\n0 1 0 0\n1 0 1 0", "output": "9" }, { "input": "4 4\n0 0 0 0\n1 0 0 1\n0 1 1 0\n0 1 0 0", "output": "20" }, { "input": "1 5\n1 1 0 0 0", "output": "3" }, { "input": "2 10\n0 0 0 0 0 0 0 1 0 0\n1 0 0 0 0 0 0 0 0 0", "output": "20" }, { "input": "3 ...
1,000
5,939,200
0
1,559
4
Registration System
[ "data structures", "hashing", "implementation" ]
C. Registration system
5
64
A new e-mail service "Berlandesk" is going to be opened in Berland in the near future. The site administration wants to launch their project as soon as possible, that's why they ask you to help. You're suggested to implement the prototype of site registration system. The system should work on the following principle. ...
The first line contains number *n* (1<=≤<=*n*<=≤<=105). The following *n* lines contain the requests to the system. Each request is a non-empty line, and consists of not more than 32 characters, which are all lowercase Latin letters.
Print *n* lines, which are system responses to the requests: OK in case of successful registration, or a prompt with a new name, if the requested name is already taken.
[ "4\nabacaba\nacaba\nabacaba\nacab\n", "6\nfirst\nfirst\nsecond\nsecond\nthird\nthird\n" ]
[ "OK\nOK\nabacaba1\nOK\n", "OK\nfirst1\nOK\nsecond1\nOK\nthird1\n" ]
none
[ { "input": "4\nabacaba\nacaba\nabacaba\nacab", "output": "OK\nOK\nabacaba1\nOK" }, { "input": "6\nfirst\nfirst\nsecond\nsecond\nthird\nthird", "output": "OK\nfirst1\nOK\nsecond1\nOK\nthird1" }, { "input": "1\nn", "output": "OK" }, { "input": "2\nu\nu", "output": "OK\nu1" ...
92
0
0
1,564
336
Vasily the Bear and Fly
[ "math" ]
null
null
One beautiful day Vasily the bear painted 2*m* circles of the same radius *R* on a coordinate plane. Circles with numbers from 1 to *m* had centers at points (2*R*<=-<=*R*,<=0), (4*R*<=-<=*R*,<=0), ..., (2*Rm*<=-<=*R*,<=0), respectively. Circles with numbers from *m*<=+<=1 to 2*m* had centers at points (2*R*<=-<=*R*,<=...
The first line contains two integers *m*,<=*R* (1<=≤<=*m*<=≤<=105, 1<=≤<=*R*<=≤<=10).
In a single line print a single real number — the answer to the problem. The answer will be considered correct if its absolute or relative error doesn't exceed 10<=-<=6.
[ "1 1\n", "2 2\n" ]
[ "2.0000000000\n", "5.4142135624\n" ]
<img class="tex-graphics" src="https://espresso.codeforces.com/9fe384073741e20965ddc4bf162afd3a604b6b39.png" style="max-width: 100.0%;max-height: 100.0%;"/> Figure to the second sample
[ { "input": "1 1", "output": "2.0000000000" }, { "input": "2 2", "output": "5.4142135624" }, { "input": "100000 3", "output": "200002.4853316681" }, { "input": "2344 5", "output": "7817.4790439982" }, { "input": "999 10", "output": "6668.3010410807" }, { ...
686
0
3
1,568
468
Hack it!
[ "binary search", "constructive algorithms", "math" ]
null
null
Little X has met the following problem recently. Let's define *f*(*x*) as the sum of digits in decimal representation of number *x* (for example, *f*(1234)<==<=1<=+<=2<=+<=3<=+<=4). You are to calculate Of course Little X has solved this problem quickly, has locked it, and then has tried to hack others. He has seen...
The first line contains a single integer *a* (1<=≤<=*a*<=≤<=1018).
Print two integers: *l*,<=*r* (1<=≤<=*l*<=≤<=*r*<=&lt;<=10200) — the required test data. Leading zeros aren't allowed. It's guaranteed that the solution exists.
[ "46\n", "126444381000032\n" ]
[ "1 10\n", "2333333 2333333333333\n" ]
none
[ { "input": "46", "output": "1 10" }, { "input": "126444381000032", "output": "2333333 2333333333333" }, { "input": "69645082595", "output": "613752823618441225798858488535 713259406474207764329704856394" }, { "input": "70602205995", "output": "11 2492213340204320744986569...
62
0
3
1,574
534
Covered Path
[ "dp", "greedy", "math" ]
null
null
The on-board computer on Polycarp's car measured that the car speed at the beginning of some section of the path equals *v*1 meters per second, and in the end it is *v*2 meters per second. We know that this section of the route took exactly *t* seconds to pass. Assuming that at each of the seconds the speed is constan...
The first line contains two integers *v*1 and *v*2 (1<=≤<=*v*1,<=*v*2<=≤<=100) — the speeds in meters per second at the beginning of the segment and at the end of the segment, respectively. The second line contains two integers *t* (2<=≤<=*t*<=≤<=100) — the time when the car moves along the segment in seconds, *d* (0<...
Print the maximum possible length of the path segment in meters.
[ "5 6\n4 2\n", "10 10\n10 0\n" ]
[ "26", "100" ]
In the first sample the sequence of speeds of Polycarpus' car can look as follows: 5, 7, 8, 6. Thus, the total path is 5 + 7 + 8 + 6 = 26 meters. In the second sample, as *d* = 0, the car covers the whole segment at constant speed *v* = 10. In *t* = 10 seconds it covers the distance of 100 meters.
[ { "input": "5 6\n4 2", "output": "26" }, { "input": "10 10\n10 0", "output": "100" }, { "input": "87 87\n2 10", "output": "174" }, { "input": "1 11\n6 2", "output": "36" }, { "input": "100 10\n10 10", "output": "550" }, { "input": "1 1\n100 10", "o...
108
0
0
1,575
962
Equator
[ "implementation" ]
null
null
Polycarp has created his own training plan to prepare for the programming contests. He will train for $n$ days, all days are numbered from $1$ to $n$, beginning from the first. On the $i$-th day Polycarp will necessarily solve $a_i$ problems. One evening Polycarp plans to celebrate the equator. He will celebrate it on...
The first line contains a single integer $n$ ($1 \le n \le 200\,000$) — the number of days to prepare for the programming contests. The second line contains a sequence $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10\,000$), where $a_i$ equals to the number of problems, which Polycarp will solve on the $i$-th day.
Print the index of the day when Polycarp will celebrate the equator.
[ "4\n1 3 2 1\n", "6\n2 2 2 2 2 2\n" ]
[ "2\n", "3\n" ]
In the first example Polycarp will celebrate the equator on the evening of the second day, because up to this day (inclusive) he will solve $4$ out of $7$ scheduled problems on four days of the training. In the second example Polycarp will celebrate the equator on the evening of the third day, because up to this day (...
[ { "input": "4\n1 3 2 1", "output": "2" }, { "input": "6\n2 2 2 2 2 2", "output": "3" }, { "input": "1\n10000", "output": "1" }, { "input": "3\n2 1 1", "output": "1" }, { "input": "2\n1 3", "output": "2" }, { "input": "4\n2 1 1 3", "output": "3" }...
171
20,582,400
3
1,579
1,003
Coins and Queries
[ "greedy" ]
null
null
Polycarp has $n$ coins, the value of the $i$-th coin is $a_i$. It is guaranteed that all the values are integer powers of $2$ (i.e. $a_i = 2^d$ for some non-negative integer number $d$). Polycarp wants to know answers on $q$ queries. The $j$-th query is described as integer number $b_j$. The answer to the query is the...
The first line of the input contains two integers $n$ and $q$ ($1 \le n, q \le 2 \cdot 10^5$) — the number of coins and the number of queries. The second line of the input contains $n$ integers $a_1, a_2, \dots, a_n$ — values of coins ($1 \le a_i \le 2 \cdot 10^9$). It is guaranteed that all $a_i$ are integer powers o...
Print $q$ integers $ans_j$. The $j$-th integer must be equal to the answer on the $j$-th query. If Polycarp can't obtain the value $b_j$ the answer to the $j$-th query is -1.
[ "5 4\n2 4 8 2 4\n8\n5\n14\n10\n" ]
[ "1\n-1\n3\n2\n" ]
none
[ { "input": "5 4\n2 4 8 2 4\n8\n5\n14\n10", "output": "1\n-1\n3\n2" }, { "input": "3 3\n1 1 1\n1\n2\n3", "output": "1\n2\n3" }, { "input": "4 1\n2 4 16 32\n14", "output": "-1" }, { "input": "1 10\n8\n1\n2\n3\n4\n5\n6\n7\n8\n9\n16", "output": "-1\n-1\n-1\n-1\n-1\n-1\n-1\n1\...
124
2,150,400
-1
1,580
26
Regular Bracket Sequence
[ "greedy" ]
B. Regular Bracket Sequence
5
256
A bracket sequence is called regular if it is possible to obtain correct arithmetic expression by inserting characters «+» and «1» into this sequence. For example, sequences «(())()», «()» and «(()(()))» are regular, while «)(», «(()» and «(()))(» are not. One day Johnny got bracket sequence. He decided to remove some...
Input consists of a single line with non-empty string of «(» and «)» characters. Its length does not exceed 106.
Output the maximum possible length of a regular bracket sequence.
[ "(()))(\n", "((()())\n" ]
[ "4\n", "6\n" ]
none
[ { "input": "(()))(", "output": "4" }, { "input": "((()())", "output": "6" }, { "input": "(", "output": "0" }, { "input": ")", "output": "0" }, { "input": ")(()(", "output": "2" }, { "input": "))))))(", "output": "0" }, { "input": "()()(()((...
92
0
0
1,585
518
Vitaly and Strings
[ "constructive algorithms", "strings" ]
null
null
Vitaly is a diligent student who never missed a lesson in his five years of studying in the university. He always does his homework on time and passes his exams in time. During the last lesson the teacher has provided two strings *s* and *t* to Vitaly. The strings have the same length, they consist of lowercase Engli...
The first line contains string *s* (1<=≤<=|*s*|<=≤<=100), consisting of lowercase English letters. Here, |*s*| denotes the length of the string. The second line contains string *t* (|*t*|<==<=|*s*|), consisting of lowercase English letters. It is guaranteed that the lengths of strings *s* and *t* are the same and str...
If the string that meets the given requirements doesn't exist, print a single string "No such string" (without the quotes). If such string exists, print it. If there are multiple valid strings, you may print any of them.
[ "a\nc\n", "aaa\nzzz\n", "abcdefg\nabcdefh\n" ]
[ "b\n", "kkk\n", "No such string\n" ]
String *s* = *s*<sub class="lower-index">1</sub>*s*<sub class="lower-index">2</sub>... *s*<sub class="lower-index">*n*</sub> is said to be lexicographically smaller than *t* = *t*<sub class="lower-index">1</sub>*t*<sub class="lower-index">2</sub>... *t*<sub class="lower-index">*n*</sub>, if there exists such *i*, that ...
[ { "input": "a\nc", "output": "b" }, { "input": "aaa\nzzz", "output": "kkk" }, { "input": "abcdefg\nabcdefh", "output": "No such string" }, { "input": "abcdefg\nabcfefg", "output": "abcdefh" }, { "input": "frt\nfru", "output": "No such string" }, { "inp...
46
0
0
1,589
691
s-palindrome
[ "implementation", "strings" ]
null
null
Let's call a string "s-palindrome" if it is symmetric about the middle of the string. For example, the string "oHo" is "s-palindrome", but the string "aa" is not. The string "aa" is not "s-palindrome", because the second half of it is not a mirror reflection of the first half. You are given a string *s*. Check if the ...
The only line contains the string *s* (1<=≤<=|*s*|<=≤<=1000) which consists of only English letters.
Print "TAK" if the string *s* is "s-palindrome" and "NIE" otherwise.
[ "oXoxoXo\n", "bod\n", "ER\n" ]
[ "TAK\n", "TAK\n", "NIE\n" ]
none
[ { "input": "oXoxoXo", "output": "TAK" }, { "input": "bod", "output": "TAK" }, { "input": "ER", "output": "NIE" }, { "input": "o", "output": "TAK" }, { "input": "a", "output": "NIE" }, { "input": "opo", "output": "NIE" }, { "input": "HCMoxkg...
93
0
0
1,590
274
k-Multiple Free Set
[ "binary search", "greedy", "sortings" ]
null
null
A *k*-multiple free set is a set of integers where there is no pair of integers where one is equal to another integer multiplied by *k*. That is, there are no two integers *x* and *y* (*x*<=&lt;<=*y*) from the set, such that *y*<==<=*x*·*k*. You're given a set of *n* distinct positive integers. Your task is to find th...
The first line of the input contains two integers *n* and *k* (1<=≤<=*n*<=≤<=105,<=1<=≤<=*k*<=≤<=109). The next line contains a list of *n* distinct positive integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=109). All the numbers in the lines are separated by single spaces.
On the only line of the output print the size of the largest *k*-multiple free subset of {*a*1,<=*a*2,<=...,<=*a**n*}.
[ "6 2\n2 3 6 5 4 10\n" ]
[ "3\n" ]
In the sample input one of the possible maximum 2-multiple free subsets is {4, 5, 6}.
[ { "input": "6 2\n2 3 6 5 4 10", "output": "3" }, { "input": "10 2\n1 2 3 4 5 6 7 8 9 10", "output": "6" }, { "input": "1 1\n1", "output": "1" }, { "input": "100 2\n191 17 61 40 77 95 128 88 26 69 79 10 131 106 142 152 68 39 182 53 83 81 6 89 65 148 33 22 5 47 107 121 52 163 1...
2,000
8,294,400
0
1,592
676
Vasya and String
[ "binary search", "dp", "strings", "two pointers" ]
null
null
High school student Vasya got a string of length *n* as a birthday present. This string consists of letters 'a' and 'b' only. Vasya denotes beauty of the string as the maximum length of a substring (consecutive subsequence) consisting of equal letters. Vasya can change no more than *k* characters of the original strin...
The first line of the input contains two integers *n* and *k* (1<=≤<=*n*<=≤<=100<=000,<=0<=≤<=*k*<=≤<=*n*) — the length of the string and the maximum number of characters to change. The second line contains the string, consisting of letters 'a' and 'b' only.
Print the only integer — the maximum beauty of the string Vasya can achieve by changing no more than *k* characters.
[ "4 2\nabba\n", "8 1\naabaabaa\n" ]
[ "4\n", "5\n" ]
In the first sample, Vasya can obtain both strings "aaaa" and "bbbb". In the second sample, the optimal answer is obtained with the string "aaaaabaa" or with the string "aabaaaaa".
[ { "input": "4 2\nabba", "output": "4" }, { "input": "8 1\naabaabaa", "output": "5" }, { "input": "1 0\na", "output": "1" }, { "input": "1 1\nb", "output": "1" }, { "input": "1 0\nb", "output": "1" }, { "input": "1 1\na", "output": "1" }, { ...
31
0
0
1,594
505
Mr. Kitayuta's Gift
[ "brute force", "implementation", "strings" ]
null
null
Mr. Kitayuta has kindly given you a string *s* consisting of lowercase English letters. You are asked to insert exactly one lowercase English letter into *s* to make it a palindrome. A palindrome is a string that reads the same forward and backward. For example, "noon", "testset" and "a" are all palindromes, while "tes...
The only line of the input contains a string *s* (1<=≤<=|*s*|<=≤<=10). Each character in *s* is a lowercase English letter.
If it is possible to turn *s* into a palindrome by inserting one lowercase English letter, print the resulting string in a single line. Otherwise, print "NA" (without quotes, case-sensitive). In case there is more than one solution, any of them will be accepted.
[ "revive\n", "ee\n", "kitayuta\n" ]
[ "reviver\n", "eye", "NA\n" ]
For the first sample, insert 'r' to the end of "revive" to obtain a palindrome "reviver". For the second sample, there is more than one solution. For example, "eve" will also be accepted. For the third sample, it is not possible to turn "kitayuta" into a palindrome by just inserting one letter.
[ { "input": "revive", "output": "reviver" }, { "input": "ee", "output": "eee" }, { "input": "kitayuta", "output": "NA" }, { "input": "evima", "output": "NA" }, { "input": "a", "output": "aa" }, { "input": "yutampo", "output": "NA" }, { "inpu...
93
0
0
1,598
111
Petya and Inequiations
[ "greedy" ]
A. Petya and Inequiations
2
256
Little Petya loves inequations. Help him find *n* positive integers *a*1,<=*a*2,<=...,<=*a**n*, such that the following two conditions are satisfied: - *a*12<=+<=*a*22<=+<=...<=+<=*a**n*2<=≥<=*x*- *a*1<=+<=*a*2<=+<=...<=+<=*a**n*<=≤<=*y*
The first line contains three space-separated integers *n*, *x* and *y* (1<=≤<=*n*<=≤<=105,<=1<=≤<=*x*<=≤<=1012,<=1<=≤<=*y*<=≤<=106). Please do not use the %lld specificator to read or write 64-bit integers in С++. It is recommended to use cin, cout streams or the %I64d specificator.
Print *n* positive integers that satisfy the conditions, one integer per line. If such numbers do not exist, print a single number "-1". If there are several solutions, print any of them.
[ "5 15 15\n", "2 3 2\n", "1 99 11\n" ]
[ "4\n4\n1\n1\n2\n", "-1\n", "11\n" ]
none
[ { "input": "5 15 15", "output": "11\n1\n1\n1\n1" }, { "input": "2 3 2", "output": "-1" }, { "input": "1 99 11", "output": "11" }, { "input": "100000 810000099998 1000000", "output": "900001\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n...
436
8,089,600
3.875932
1,603
175
Robot Bicorn Attack
[ "brute force", "implementation" ]
null
null
Vasya plays Robot Bicorn Attack. The game consists of three rounds. For each one a non-negative integer amount of points is given. The result of the game is the sum of obtained points. Vasya has already played three rounds and wrote obtained points one by one (without leading zeros) into the string *s*. Vasya decided ...
The only line of input contains non-empty string *s* obtained by Vasya. The string consists of digits only. The string length does not exceed 30 characters.
Print the only number — the maximum amount of points Vasya could get. If Vasya is wrong and the string could not be obtained according to the rules then output number -1.
[ "1234\n", "9000\n", "0009\n" ]
[ "37\n", "90\n", "-1\n" ]
In the first example the string must be split into numbers 1, 2 and 34. In the second example the string must be split into numbers 90, 0 and 0. In the third example the string is incorrect, because after splitting the string into 3 numbers number 00 or 09 will be obtained, but numbers cannot have leading zeroes.
[ { "input": "1234", "output": "37" }, { "input": "9000", "output": "90" }, { "input": "0009", "output": "-1" }, { "input": "100000010000001000000", "output": "3000000" }, { "input": "1000000011", "output": "1000011" }, { "input": "9991", "output": "...
61
5,529,600
0
1,608
598
Igor In the Museum
[ "dfs and similar", "graphs", "shortest paths" ]
null
null
Igor is in the museum and he wants to see as many pictures as possible. Museum can be represented as a rectangular field of *n*<=×<=*m* cells. Each cell is either empty or impassable. Empty cells are marked with '.', impassable cells are marked with '*'. Every two adjacent cells of different types (one empty and one i...
First line of the input contains three integers *n*, *m* and *k* (3<=≤<=*n*,<=*m*<=≤<=1000,<=1<=≤<=*k*<=≤<=*min*(*n*·*m*,<=100<=000)) — the museum dimensions and the number of starting positions to process. Each of the next *n* lines contains *m* symbols '.', '*' — the description of the museum. It is guaranteed that ...
Print *k* integers — the maximum number of pictures, that Igor can see if he starts in corresponding position.
[ "5 6 3\n******\n*..*.*\n******\n*....*\n******\n2 2\n2 5\n4 3\n", "4 4 1\n****\n*..*\n*.**\n****\n3 2\n" ]
[ "6\n4\n10\n", "8\n" ]
none
[ { "input": "5 6 3\n******\n*..*.*\n******\n*....*\n******\n2 2\n2 5\n4 3", "output": "6\n4\n10" }, { "input": "4 4 1\n****\n*..*\n*.**\n****\n3 2", "output": "8" }, { "input": "3 3 1\n***\n*.*\n***\n2 2", "output": "4" }, { "input": "5 5 10\n*****\n*...*\n*..**\n*.***\n*****\...
1,000
27,852,800
0
1,609
938
Word Correction
[ "implementation" ]
null
null
Victor tries to write his own text editor, with word correction included. However, the rules of word correction are really strange. Victor thinks that if a word contains two consecutive vowels, then it's kinda weird and it needs to be replaced. So the word corrector works in such a way: as long as there are two consec...
The first line contains one integer *n* (1<=≤<=*n*<=≤<=100) — the number of letters in word *s* before the correction. The second line contains a string *s* consisting of exactly *n* lowercase Latin letters — the word before the correction.
Output the word *s* after the correction.
[ "5\nweird\n", "4\nword\n", "5\naaeaa\n" ]
[ "werd\n", "word\n", "a\n" ]
Explanations of the examples: 1. There is only one replace: weird <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/70a0795f45d32287dba0eb83fc4a3f470c6e5537.png" style="max-width: 100.0%;max-height: 100.0%;"/> werd;1. No replace needed since there are no two consecutive vowels;1. aaeaa <i...
[ { "input": "5\nweird", "output": "werd" }, { "input": "4\nword", "output": "word" }, { "input": "5\naaeaa", "output": "a" }, { "input": "100\naaaaabbbbboyoyoyoyoyacadabbbbbiuiufgiuiuaahjabbbklboyoyoyoyoyaaaaabbbbbiuiuiuiuiuaaaaabbbbbeyiyuyzyw", "output": "abbbbbocadabbbbb...
140
0
3
1,610
245
Queries for Number of Palindromes
[ "dp", "hashing", "strings" ]
null
null
You've got a string *s*<==<=*s*1*s*2... *s*|*s*| of length |*s*|, consisting of lowercase English letters. There also are *q* queries, each query is described by two integers *l**i*,<=*r**i* (1<=≤<=*l**i*<=≤<=*r**i*<=≤<=|*s*|). The answer to the query is the number of substrings of string *s*[*l**i*... *r**i*], which a...
The first line contains string *s* (1<=≤<=|*s*|<=≤<=5000). The second line contains a single integer *q* (1<=≤<=*q*<=≤<=106) — the number of queries. Next *q* lines contain the queries. The *i*-th of these lines contains two space-separated integers *l**i*,<=*r**i* (1<=≤<=*l**i*<=≤<=*r**i*<=≤<=|*s*|) — the description ...
Print *q* integers — the answers to the queries. Print the answers in the order, in which the queries are given in the input. Separate the printed numbers by whitespaces.
[ "caaaba\n5\n1 1\n1 4\n2 3\n4 6\n4 5\n" ]
[ "1\n7\n3\n4\n2\n" ]
Consider the fourth query in the first test case. String *s*[4... 6] = «aba». Its palindrome substrings are: «a», «b», «a», «aba».
[ { "input": "caaaba\n5\n1 1\n1 4\n2 3\n4 6\n4 5", "output": "1\n7\n3\n4\n2" }, { "input": "a\n100\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 1\n1 ...
5,000
34,918,400
0
1,616
221
Little Elephant and Function
[ "implementation", "math" ]
null
null
The Little Elephant enjoys recursive functions. This time he enjoys the sorting function. Let *a* is a permutation of an integers from 1 to *n*, inclusive, and *a**i* denotes the *i*-th element of the permutation. The Little Elephant's recursive function *f*(*x*), that sorts the first *x* permutation's elements, works...
A single line contains integer *n* (1<=≤<=*n*<=≤<=1000) — the size of permutation.
In a single line print *n* distinct integers from 1 to *n* — the required permutation. Numbers in a line should be separated by spaces. It is guaranteed that the answer exists.
[ "1\n", "2\n" ]
[ "1 ", "2 1 " ]
none
[ { "input": "1", "output": "1 " }, { "input": "2", "output": "2 1 " }, { "input": "3", "output": "3 1 2 " }, { "input": "4", "output": "4 1 2 3 " }, { "input": "5", "output": "5 1 2 3 4 " }, { "input": "6", "output": "6 1 2 3 4 5 " }, { "inp...
248
0
0
1,624
712
Memory and Crow
[ "implementation", "math" ]
null
null
There are *n* integers *b*1,<=*b*2,<=...,<=*b**n* written in a row. For all *i* from 1 to *n*, values *a**i* are defined by the crows performing the following procedure: - The crow sets *a**i* initially 0. - The crow then adds *b**i* to *a**i*, subtracts *b**i*<=+<=1, adds the *b**i*<=+<=2 number, and so on until th...
The first line of the input contains a single integer *n* (2<=≤<=*n*<=≤<=100<=000) — the number of integers written in the row. The next line contains *n*, the *i*'th of which is *a**i* (<=-<=109<=≤<=*a**i*<=≤<=109) — the value of the *i*'th number.
Print *n* integers corresponding to the sequence *b*1,<=*b*2,<=...,<=*b**n*. It's guaranteed that the answer is unique and fits in 32-bit integer type.
[ "5\n6 -4 8 -2 3\n", "5\n3 -2 -1 5 6\n" ]
[ "2 4 6 1 3 \n", "1 -3 4 11 6 \n" ]
In the first sample test, the crows report the numbers 6, - 4, 8, - 2, and 3 when he starts at indices 1, 2, 3, 4 and 5 respectively. It is easy to check that the sequence 2 4 6 1 3 satisfies the reports. For example, 6 = 2 - 4 + 6 - 1 + 3, and  - 4 = 4 - 6 + 1 - 3. In the second sample test, the sequence 1,  - 3, 4, ...
[ { "input": "5\n6 -4 8 -2 3", "output": "2 4 6 1 3 " }, { "input": "5\n3 -2 -1 5 6", "output": "1 -3 4 11 6 " }, { "input": "10\n13 -2 532 -63 -23 -63 -64 -23 12 10", "output": "11 530 469 -86 -86 -127 -87 -11 22 10 " }, { "input": "10\n0 0 0 0 0 0 0 0 0 0", "output": "0 0...
405
8,396,800
3
1,625
808
Lucky Year
[ "implementation" ]
null
null
Apart from having lots of holidays throughout the year, residents of Berland also have whole lucky years. Year is considered lucky if it has no more than 1 non-zero digit in its number. So years 100, 40000, 5 are lucky and 12, 3001 and 12345 are not. You are given current year in Berland. Your task is to find how long...
The first line contains integer number *n* (1<=≤<=*n*<=≤<=109) — current year in Berland.
Output amount of years from the current year to the next lucky one.
[ "4\n", "201\n", "4000\n" ]
[ "1\n", "99\n", "1000\n" ]
In the first example next lucky year is 5. In the second one — 300. In the third — 5000.
[ { "input": "4", "output": "1" }, { "input": "201", "output": "99" }, { "input": "4000", "output": "1000" }, { "input": "9", "output": "1" }, { "input": "10", "output": "10" }, { "input": "1", "output": "1" }, { "input": "100000000", "ou...
155
0
3
1,628
761
Dasha and Stairs
[ "brute force", "constructive algorithms", "implementation", "math" ]
null
null
On her way to programming school tiger Dasha faced her first test — a huge staircase! The steps were numbered from one to infinity. As we know, tigers are very fond of all striped things, it is possible that it has something to do with their color. So on some interval of her way she calculated two values — the number ...
In the only line you are given two integers *a*, *b* (0<=≤<=*a*,<=*b*<=≤<=100) — the number of even and odd steps, accordingly.
In the only line print "YES", if the interval of steps described above exists, and "NO" otherwise.
[ "2 3\n", "3 1\n" ]
[ "YES\n", "NO\n" ]
In the first example one of suitable intervals is from 1 to 5. The interval contains two even steps — 2 and 4, and three odd: 1, 3 and 5.
[ { "input": "2 3", "output": "YES" }, { "input": "3 1", "output": "NO" }, { "input": "5 4", "output": "YES" }, { "input": "9 9", "output": "YES" }, { "input": "85 95", "output": "NO" }, { "input": "0 1", "output": "YES" }, { "input": "89 25"...
109
0
3
1,629
20
BerOS file system
[ "implementation" ]
A. BerOS file system
2
64
The new operating system BerOS has a nice feature. It is possible to use any number of characters '/' as a delimiter in path instead of one traditional '/'. For example, strings //usr///local//nginx/sbin// and /usr/local/nginx///sbin are equivalent. The character '/' (or some sequence of such characters) at the end of ...
The first line of the input contains only lowercase Latin letters and character '/' — the path to some directory. All paths start with at least one character '/'. The length of the given line is no more than 100 characters, it is not empty.
The path in normalized form.
[ "//usr///local//nginx/sbin\n" ]
[ "/usr/local/nginx/sbin\n" ]
none
[ { "input": "//usr///local//nginx/sbin", "output": "/usr/local/nginx/sbin" }, { "input": "////a//b/////g", "output": "/a/b/g" }, { "input": "/a/b/c", "output": "/a/b/c" }, { "input": "/", "output": "/" }, { "input": "////", "output": "/" }, { "input": "...
186
0
3.9535
1,631
452
Eevee
[ "brute force", "implementation", "strings" ]
null
null
You are solving the crossword problem K from IPSC 2014. You solved all the clues except for one: who does Eevee evolve into? You are not very into pokemons, but quick googling helped you find out, that Eevee can evolve into eight different pokemons: Vaporeon, Jolteon, Flareon, Espeon, Umbreon, Leafeon, Glaceon, and Syl...
First line contains an integer *n* (6<=≤<=*n*<=≤<=8) – the length of the string. Next line contains a string consisting of *n* characters, each of which is either a lower case english letter (indicating a known letter) or a dot character (indicating an empty cell in the crossword).
Print a name of the pokemon that Eevee can evolve into that matches the pattern in the input. Use lower case letters only to print the name (in particular, do not capitalize the first letter).
[ "7\nj......\n", "7\n...feon\n", "7\n.l.r.o.\n" ]
[ "jolteon\n", "leafeon\n", "flareon\n" ]
Here's a set of names in a form you can paste into your solution: ["vaporeon", "jolteon", "flareon", "espeon", "umbreon", "leafeon", "glaceon", "sylveon"] {"vaporeon", "jolteon", "flareon", "espeon", "umbreon", "leafeon", "glaceon", "sylveon"}
[ { "input": "7\n...feon", "output": "leafeon" }, { "input": "7\n.l.r.o.", "output": "flareon" }, { "input": "6\n.s..o.", "output": "espeon" }, { "input": "7\nglaceon", "output": "glaceon" }, { "input": "8\n.a.o.e.n", "output": "vaporeon" }, { "input": "...
61
0
0
1,633
570
Tree Requests
[ "binary search", "bitmasks", "constructive algorithms", "dfs and similar", "graphs", "trees" ]
null
null
Roman planted a tree consisting of *n* vertices. Each vertex contains a lowercase English letter. Vertex 1 is the root of the tree, each of the *n*<=-<=1 remaining vertices has a parent in the tree. Vertex is connected with its parent by an edge. The parent of vertex *i* is vertex *p**i*, the parent index is always les...
The first line contains two integers *n*, *m* (1<=≤<=*n*,<=*m*<=≤<=500<=000) — the number of nodes in the tree and queries, respectively. The following line contains *n*<=-<=1 integers *p*2,<=*p*3,<=...,<=*p**n* — the parents of vertices from the second to the *n*-th (1<=≤<=*p**i*<=&lt;<=*i*). The next line contains ...
Print *m* lines. In the *i*-th line print "Yes" (without the quotes), if in the *i*-th query you can make a palindrome from the letters written on the vertices, otherwise print "No" (without the quotes).
[ "6 5\n1 1 1 3 3\nzacccd\n1 1\n3 3\n4 1\n6 1\n1 2\n" ]
[ "Yes\nNo\nYes\nYes\nYes\n" ]
String *s* is a palindrome if reads the same from left to right and from right to left. In particular, an empty string is a palindrome. Clarification for the sample test. In the first query there exists only a vertex 1 satisfying all the conditions, we can form a palindrome "z". In the second query vertices 5 and 6 ...
[ { "input": "6 5\n1 1 1 3 3\nzacccd\n1 1\n3 3\n4 1\n6 1\n1 2", "output": "Yes\nNo\nYes\nYes\nYes" }, { "input": "5 6\n1 1 2 3\ncbcab\n3 1\n5 2\n1 3\n4 1\n4 2\n1 1", "output": "Yes\nYes\nNo\nYes\nYes\nYes" }, { "input": "5 6\n1 2 2 1\nbaabb\n1 1\n1 2\n5 1\n4 1\n4 2\n3 2", "output": "Ye...
2,000
217,907,200
0
1,634
979
Kuro and Walking Route
[ "dfs and similar", "trees" ]
null
null
Kuro is living in a country called Uberland, consisting of $n$ towns, numbered from $1$ to $n$, and $n - 1$ bidirectional roads connecting these towns. It is possible to reach each town from any other. Each road connects two towns $a$ and $b$. Kuro loves walking and he is planning to take a walking marathon, in which h...
The first line contains three integers $n$, $x$ and $y$ ($1 \leq n \leq 3 \cdot 10^5$, $1 \leq x, y \leq n$, $x \ne y$) - the number of towns, index of the town Flowrisa and index of the town Beetopia, respectively. $n - 1$ lines follow, each line contains two integers $a$ and $b$ ($1 \leq a, b \leq n$, $a \ne b$), de...
A single integer resembles the number of pair of towns $(u, v)$ that Kuro can use as his walking route.
[ "3 1 3\n1 2\n2 3\n", "3 1 3\n1 2\n1 3\n" ]
[ "5", "4" ]
On the first example, Kuro can choose these pairs: - $(1, 2)$: his route would be $1 \rightarrow 2$, - $(2, 3)$: his route would be $2 \rightarrow 3$, - $(3, 2)$: his route would be $3 \rightarrow 2$, - $(2, 1)$: his route would be $2 \rightarrow 1$, - $(3, 1)$: his route would be $3 \rightarrow 2 \rightarrow 1$...
[ { "input": "3 1 3\n1 2\n2 3", "output": "5" }, { "input": "3 1 3\n1 2\n1 3", "output": "4" }, { "input": "61 26 12\n33 38\n32 8\n27 59\n1 21\n61 57\n61 22\n35 18\n61 14\n39 56\n50 10\n1 42\n21 43\n61 41\n31 30\n35 9\n23 28\n39 34\n39 4\n39 25\n27 60\n45 51\n1 11\n35 26\n29 15\n23 44\n31 ...
109
1,024,000
0
1,637
630
Again Twenty Five!
[ "number theory" ]
null
null
The HR manager was disappointed again. The last applicant failed the interview the same way as 24 previous ones. "Do I give such a hard task?" — the HR manager thought. "Just raise number 5 to the power of *n* and get last two digits of the number. Yes, of course, *n* can be rather big, and one cannot find the power us...
The only line of the input contains a single integer *n* (2<=≤<=*n*<=≤<=2·1018) — the power in which you need to raise number 5.
Output the last two digits of 5*n* without spaces between them.
[ "2\n" ]
[ "25" ]
none
[ { "input": "2", "output": "25" }, { "input": "7", "output": "25" }, { "input": "1000000000000000000", "output": "25" }, { "input": "2000000000000000000", "output": "25" }, { "input": "987654321012345678", "output": "25" } ]
46
0
0
1,638
429
Xor-tree
[ "dfs and similar", "trees" ]
null
null
Iahub is very proud of his recent discovery, propagating trees. Right now, he invented a new tree, called xor-tree. After this new revolutionary discovery, he invented a game for kids which uses xor-trees. The game is played on a tree having *n* nodes, numbered from 1 to *n*. Each node *i* has an initial value *init**...
The first line contains an integer *n* (1<=≤<=*n*<=≤<=105). Each of the next *n*<=-<=1 lines contains two integers *u**i* and *v**i* (1<=≤<=*u**i*,<=*v**i*<=≤<=*n*; *u**i*<=≠<=*v**i*) meaning there is an edge between nodes *u**i* and *v**i*. The next line contains *n* integer numbers, the *i*-th of them corresponds t...
In the first line output an integer number *cnt*, representing the minimal number of operations you perform. Each of the next *cnt* lines should contain an integer *x**i*, representing that you pick a node *x**i*.
[ "10\n2 1\n3 1\n4 2\n5 1\n6 2\n7 5\n8 6\n9 8\n10 5\n1 0 1 1 0 1 0 1 0 1\n1 0 1 0 0 1 1 1 0 1\n" ]
[ "2\n4\n7\n" ]
none
[ { "input": "10\n2 1\n3 1\n4 2\n5 1\n6 2\n7 5\n8 6\n9 8\n10 5\n1 0 1 1 0 1 0 1 0 1\n1 0 1 0 0 1 1 1 0 1", "output": "2\n4\n7" }, { "input": "15\n2 1\n3 2\n4 3\n5 4\n6 5\n7 6\n8 7\n9 8\n10 9\n11 10\n12 11\n13 12\n14 13\n15 14\n0 1 0 0 1 1 1 1 1 1 0 0 0 1 1\n1 1 1 1 0 0 1 1 0 1 0 0 1 1 0", "output"...
1,000
20,582,400
0
1,641
845
Chess Tourney
[ "implementation", "sortings" ]
null
null
Berland annual chess tournament is coming! Organizers have gathered 2·*n* chess players who should be divided into two teams with *n* people each. The first team is sponsored by BerOil and the second team is sponsored by BerMobile. Obviously, organizers should guarantee the win for the team of BerOil. Thus, organizer...
The first line contains one integer *n* (1<=≤<=*n*<=≤<=100). The second line contains 2·*n* integers *a*1,<=*a*2,<=... *a*2*n* (1<=≤<=*a**i*<=≤<=1000).
If it's possible to divide all 2·*n* players into two teams with *n* people each so that the player from the first team in every pair wins regardless of the results of the drawing, then print "YES". Otherwise print "NO".
[ "2\n1 3 2 4\n", "1\n3 3\n" ]
[ "YES\n", "NO\n" ]
none
[ { "input": "2\n1 3 2 4", "output": "YES" }, { "input": "1\n3 3", "output": "NO" }, { "input": "5\n1 1 1 1 2 2 3 3 3 3", "output": "NO" }, { "input": "5\n1 1 1 1 1 2 2 2 2 2", "output": "YES" }, { "input": "10\n1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000...
109
0
3
1,644
844
Rectangles
[ "combinatorics", "math" ]
null
null
You are given *n*<=×<=*m* table. Each cell of the table is colored white or black. Find the number of non-empty sets of cells such that: 1. All cells in a set have the same color. 1. Every two cells in a set share row or column.
The first line of input contains integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=50) — the number of rows and the number of columns correspondingly. The next *n* lines of input contain descriptions of rows. There are *m* integers, separated by spaces, in each line. The number equals 0 if the corresponding cell is colored wh...
Output single integer  — the number of non-empty sets from the problem description.
[ "1 1\n0\n", "2 3\n1 0 1\n0 1 0\n" ]
[ "1\n", "8\n" ]
In the second example, there are six one-element sets. Additionally, there are two two-element sets, the first one consists of the first and the third cells of the first row, the second one consists of the first and the third cells of the second row. To sum up, there are 8 sets.
[ { "input": "1 1\n0", "output": "1" }, { "input": "2 3\n1 0 1\n0 1 0", "output": "8" }, { "input": "2 2\n1 1\n1 1", "output": "8" }, { "input": "1 10\n0 0 0 0 0 0 0 0 0 0", "output": "1023" }, { "input": "11 1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1\n1", "output": "2047"...
46
0
0
1,646
239
Two Bags of Potatoes
[ "greedy", "implementation", "math" ]
null
null
Valera had two bags of potatoes, the first of these bags contains *x* (*x*<=≥<=1) potatoes, and the second — *y* (*y*<=≥<=1) potatoes. Valera — very scattered boy, so the first bag of potatoes (it contains *x* potatoes) Valera lost. Valera remembers that the total amount of potatoes (*x*<=+<=*y*) in the two bags, first...
The first line of input contains three integers *y*, *k*, *n* (1<=≤<=*y*,<=*k*,<=*n*<=≤<=109; <=≤<=105).
Print the list of whitespace-separated integers — all possible values of *x* in ascending order. You should print each possible value of *x* exactly once. If there are no such values of *x* print a single integer -1.
[ "10 1 10\n", "10 6 40\n" ]
[ "-1\n", "2 8 14 20 26 \n" ]
none
[ { "input": "10 1 10", "output": "-1" }, { "input": "10 6 40", "output": "2 8 14 20 26 " }, { "input": "10 1 20", "output": "1 2 3 4 5 6 7 8 9 10 " }, { "input": "1 10000 1000000000", "output": "9999 19999 29999 39999 49999 59999 69999 79999 89999 99999 109999 119999 12999...
1,000
24,268,800
0
1,651
540
Combination Lock
[ "implementation" ]
null
null
Scrooge McDuck keeps his most treasured savings in a home safe with a combination lock. Each time he wants to put there the treasures that he's earned fair and square, he has to open the lock. The combination lock is represented by *n* rotating disks with digits from 0 to 9 written on them. Scrooge McDuck has to turn ...
The first line contains a single integer *n* (1<=≤<=*n*<=≤<=1000) — the number of disks on the combination lock. The second line contains a string of *n* digits — the original state of the disks. The third line contains a string of *n* digits — Scrooge McDuck's combination that opens the lock.
Print a single integer — the minimum number of moves Scrooge McDuck needs to open the lock.
[ "5\n82195\n64723\n" ]
[ "13\n" ]
In the sample he needs 13 moves: - 1 disk: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/b8967f65a723782358b93eff9ce69f336817cf70.png" style="max-width: 100.0%;max-height: 100.0%;"/> - 2 disk: <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/07fa58573ece0d32...
[ { "input": "5\n82195\n64723", "output": "13" }, { "input": "12\n102021090898\n010212908089", "output": "16" }, { "input": "1\n8\n1", "output": "3" }, { "input": "2\n83\n57", "output": "7" }, { "input": "10\n0728592530\n1362615763", "output": "27" }, { ...
77
1,433,600
3
1,657
453
Little Pony and Lord Tirek
[ "data structures" ]
null
null
Lord Tirek is a centaur and the main antagonist in the season four finale episodes in the series "My Little Pony: Friendship Is Magic". In "Twilight's Kingdom" (Part 1), Tirek escapes from Tartarus and drains magic from ponies to grow stronger. The core skill of Tirek is called Absorb Mana. It takes all mana from a ma...
The first line contains an integer *n* (1<=≤<=*n*<=≤<=105) — the number of ponies. Each of the next *n* lines contains three integers *s**i*,<=*m**i*,<=*r**i* (0<=≤<=*s**i*<=≤<=*m**i*<=≤<=105; 0<=≤<=*r**i*<=≤<=105), describing a pony. The next line contains an integer *m* (1<=≤<=*m*<=≤<=105) — the number of instructi...
For each instruction, output a single line which contains a single integer, the total mana absorbed in this instruction.
[ "5\n0 10 1\n0 12 1\n0 20 1\n0 12 1\n0 10 1\n2\n5 1 5\n19 1 5\n" ]
[ "25\n58\n" ]
Every pony starts with zero mana. For the first instruction, each pony has 5 mana, so you get 25 mana in total and each pony has 0 mana after the first instruction. For the second instruction, pony 3 has 14 mana and other ponies have mana equal to their *m*<sub class="lower-index">*i*</sub>.
[]
93
307,200
-1
1,663