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__index_level_0__
int64
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none
[ "none" ]
null
null
Dima came to the horse land. There are *n* horses living in the land. Each horse in the horse land has several enemies (enmity is a symmetric relationship). The horse land isn't very hostile, so the number of enemies of each horse is at most 3. Right now the horse land is going through an election campaign. So the hor...
The first line contains two integers *n*,<=*m* — the number of horses in the horse land and the number of enemy pairs. Next *m* lines define the enemy pairs. The *i*-th line contains integers *a**i*,<=*b**i* (1<=≤<=*a**i*,<=*b**i*<=≤<=*n*; *a**i*<=≠<=*b**i*), which mean that horse *a**i* is the enemy of horse *b**i*....
Print a line, consisting of *n* characters: the *i*-th character of the line must equal "0", if the horse number *i* needs to go to the first party, otherwise this character should equal "1". If there isn't a way to divide the horses as required, print -1.
[ "3 3\n1 2\n3 2\n3 1\n", "2 1\n2 1\n", "10 6\n1 2\n1 3\n1 4\n2 3\n2 4\n3 4\n" ]
[ "100\n", "00\n", "0110000000\n" ]
none
[]
62
0
0
3,479
673
Problems for Round
[ "greedy", "implementation" ]
null
null
There are *n* problems prepared for the next Codeforces round. They are arranged in ascending order by their difficulty, and no two problems have the same difficulty. Moreover, there are *m* pairs of similar problems. Authors want to split problems between two division according to the following rules: - Problemset ...
The first line of the input contains two integers *n* and *m* (2<=≤<=*n*<=≤<=100<=000, 0<=≤<=*m*<=≤<=100<=000) — the number of problems prepared for the round and the number of pairs of similar problems, respectively. Each of the following *m* lines contains a pair of similar problems *u**i* and *v**i* (1<=≤<=*u**i*,<...
Print one integer — the number of ways to split problems in two divisions.
[ "5 2\n1 4\n5 2\n", "3 3\n1 2\n2 3\n1 3\n", "3 2\n3 1\n3 2\n" ]
[ "2\n", "0\n", "1\n" ]
In the first sample, problems 1 and 2 should be used in division 2, while problems 4 and 5 in division 1. Problem 3 may be used either in division 1 or in division 2. In the second sample, all pairs of problems are similar and there is no way to split problem between two divisions without breaking any rules. Third sa...
[ { "input": "5 2\n1 4\n5 2", "output": "2" }, { "input": "3 3\n1 2\n2 3\n1 3", "output": "0" }, { "input": "3 2\n3 1\n3 2", "output": "1" }, { "input": "2 0", "output": "1" }, { "input": "2 1\n1 2", "output": "1" }, { "input": "3 0", "output": "2" ...
46
5,120,000
0
3,494
74
Train
[ "dp", "games", "greedy" ]
B. Train
2
256
A stowaway and a controller play the following game. The train is represented by *n* wagons which are numbered with positive integers from 1 to *n* from the head to the tail. The stowaway and the controller are initially in some two different wagons. Every minute the train can be in one of two conditions — moving or ...
The first line contains three integers *n*, *m* and *k*. They represent the number of wagons in the train, the stowaway's and the controller's initial positions correspondingly (2<=≤<=*n*<=≤<=50, 1<=≤<=*m*,<=*k*<=≤<=*n*, *m*<=≠<=*k*). The second line contains the direction in which a controller moves. "to head" means ...
If the stowaway wins, print "Stowaway" without quotes. Otherwise, print "Controller" again without quotes, then, separated by a space, print the number of a minute, at which the stowaway will be caught.
[ "5 3 2\nto head\n0001001\n", "3 2 1\nto tail\n0001\n" ]
[ "Stowaway", "Controller 2" ]
none
[ { "input": "5 3 2\nto head\n0001001", "output": "Stowaway" }, { "input": "3 2 1\nto tail\n0001", "output": "Controller 2" }, { "input": "4 2 1\nto tail\n1000001", "output": "Controller 6" }, { "input": "2 1 2\nto head\n111111", "output": "Stowaway" }, { "input": "...
124
307,200
3.968428
3,516
779
Pupils Redistribution
[ "constructive algorithms", "math" ]
null
null
In Berland each high school student is characterized by academic performance — integer value between 1 and 5. In high school 0xFF there are two groups of pupils: the group *A* and the group *B*. Each group consists of exactly *n* students. An academic performance of each student is known — integer value between 1 and ...
The first line of the input contains integer number *n* (1<=≤<=*n*<=≤<=100) — number of students in both groups. The second line contains sequence of integer numbers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=5), where *a**i* is academic performance of the *i*-th student of the group *A*. The third line contains se...
Print the required minimum number of exchanges or -1, if the desired distribution of students can not be obtained.
[ "4\n5 4 4 4\n5 5 4 5\n", "6\n1 1 1 1 1 1\n5 5 5 5 5 5\n", "1\n5\n3\n", "9\n3 2 5 5 2 3 3 3 2\n4 1 4 1 1 2 4 4 1\n" ]
[ "1\n", "3\n", "-1\n", "4\n" ]
none
[ { "input": "4\n5 4 4 4\n5 5 4 5", "output": "1" }, { "input": "6\n1 1 1 1 1 1\n5 5 5 5 5 5", "output": "3" }, { "input": "1\n5\n3", "output": "-1" }, { "input": "9\n3 2 5 5 2 3 3 3 2\n4 1 4 1 1 2 4 4 1", "output": "4" }, { "input": "1\n1\n2", "output": "-1" ...
15
0
0
3,521
626
Block Towers
[ "brute force", "greedy", "math", "number theory" ]
null
null
Students in a class are making towers of blocks. Each student makes a (non-zero) tower by stacking pieces lengthwise on top of each other. *n* of the students use pieces made of two blocks and *m* of the students use pieces made of three blocks. The students don’t want to use too many blocks, but they also want to be ...
The first line of the input contains two space-separated integers *n* and *m* (0<=≤<=*n*,<=*m*<=≤<=1<=000<=000, *n*<=+<=*m*<=&gt;<=0) — the number of students using two-block pieces and the number of students using three-block pieces, respectively.
Print a single integer, denoting the minimum possible height of the tallest tower.
[ "1 3\n", "3 2\n", "5 0\n" ]
[ "9\n", "8\n", "10\n" ]
In the first case, the student using two-block pieces can make a tower of height 4, and the students using three-block pieces can make towers of height 3, 6, and 9 blocks. The tallest tower has a height of 9 blocks. In the second case, the students can make towers of heights 2, 4, and 8 with two-block pieces and tower...
[ { "input": "1 3", "output": "9" }, { "input": "3 2", "output": "8" }, { "input": "5 0", "output": "10" }, { "input": "4 2", "output": "9" }, { "input": "0 1000000", "output": "3000000" }, { "input": "1000000 1", "output": "2000000" }, { "in...
61
0
-1
3,524
733
Parade
[ "math" ]
null
null
Very soon there will be a parade of victory over alien invaders in Berland. Unfortunately, all soldiers died in the war and now the army consists of entirely new recruits, many of whom do not even know from which leg they should begin to march. The civilian population also poorly understands from which leg recruits beg...
The first line contains single integer *n* (1<=≤<=*n*<=≤<=105) — the number of columns. The next *n* lines contain the pairs of integers *l**i* and *r**i* (1<=≤<=*l**i*,<=*r**i*<=≤<=500) — the number of soldiers in the *i*-th column which start to march from the left or the right leg respectively.
Print single integer *k* — the number of the column in which soldiers need to change the leg from which they start to march, or 0 if the maximum beauty is already reached. Consider that columns are numbered from 1 to *n* in the order they are given in the input data. If there are several answers, print any of them.
[ "3\n5 6\n8 9\n10 3\n", "2\n6 5\n5 6\n", "6\n5 9\n1 3\n4 8\n4 5\n23 54\n12 32\n" ]
[ "3\n", "1\n", "0\n" ]
In the first example if you don't give the order to change the leg, the number of soldiers, who start to march from the left leg, would equal 5 + 8 + 10 = 23, and from the right leg — 6 + 9 + 3 = 18. In this case the beauty of the parade will equal |23 - 18| = 5. If you give the order to change the leg to the third co...
[ { "input": "3\n5 6\n8 9\n10 3", "output": "3" }, { "input": "2\n6 5\n5 6", "output": "1" }, { "input": "6\n5 9\n1 3\n4 8\n4 5\n23 54\n12 32", "output": "0" }, { "input": "2\n500 499\n500 500", "output": "0" }, { "input": "1\n139 252", "output": "0" }, { ...
358
2,662,400
3
3,532
340
Iahub and Permutations
[ "combinatorics", "math" ]
null
null
Iahub is so happy about inventing bubble sort graphs that he's staying all day long at the office and writing permutations. Iahubina is angry that she is no more important for Iahub. When Iahub goes away, Iahubina comes to his office and sabotage his research work. The girl finds an important permutation for the resea...
The first line contains integer *n* (2<=≤<=*n*<=≤<=2000). On the second line, there are *n* integers, representing Iahub's important permutation after Iahubina replaces some values with -1. It's guaranteed that there are no fixed points in the given permutation. Also, the given sequence contains at least two numbers ...
Output a single integer, the number of ways Iahub could recover his permutation, modulo 1000000007 (109<=+<=7).
[ "5\n-1 -1 4 3 -1\n" ]
[ "2\n" ]
For the first test example there are two permutations with no fixed points are [2, 5, 4, 3, 1] and [5, 1, 4, 3, 2]. Any other permutation would have at least one fixed point.
[ { "input": "5\n-1 -1 4 3 -1", "output": "2" }, { "input": "8\n2 4 5 3 -1 8 -1 6", "output": "1" }, { "input": "7\n-1 -1 4 -1 7 1 6", "output": "4" }, { "input": "6\n-1 -1 -1 -1 -1 -1", "output": "265" }, { "input": "2\n-1 -1", "output": "1" }, { "input...
124
7,065,600
0
3,534
0
none
[ "none" ]
null
null
You are given an array *a*1,<=*a*2,<=...,<=*a**n* consisting of *n* integers, and an integer *k*. You have to split the array into exactly *k* non-empty subsegments. You'll then compute the minimum integer on each subsegment, and take the maximum integer over the *k* obtained minimums. What is the maximum possible inte...
The first line contains two integers *n* and *k* (1<=≤<=*k*<=≤<=*n*<=≤<=<=105) — the size of the array *a* and the number of subsegments you have to split the array to. The second line contains *n* integers *a*1,<=<=*a*2,<=<=...,<=<=*a**n* (<=-<=109<=<=≤<=<=*a**i*<=≤<=<=109).
Print single integer — the maximum possible integer you can get if you split the array into *k* non-empty subsegments and take maximum of minimums on the subsegments.
[ "5 2\n1 2 3 4 5\n", "5 1\n-4 -5 -3 -2 -1\n" ]
[ "5\n", "-5\n" ]
A subsegment [*l*,  *r*] (*l* ≤ *r*) of array *a* is the sequence *a*<sub class="lower-index">*l*</sub>,  *a*<sub class="lower-index">*l* + 1</sub>,  ...,  *a*<sub class="lower-index">*r*</sub>. Splitting of array *a* of *n* elements into *k* subsegments [*l*<sub class="lower-index">1</sub>, *r*<sub class="lower-index...
[ { "input": "5 2\n1 2 3 4 5", "output": "5" }, { "input": "5 1\n-4 -5 -3 -2 -1", "output": "-5" }, { "input": "10 2\n10 9 1 -9 -7 -9 3 8 -10 5", "output": "10" }, { "input": "10 4\n-8 -1 2 -3 9 -8 4 -3 5 9", "output": "9" }, { "input": "1 1\n504262064", "output...
233
13,619,200
3
3,550
858
Tests Renumeration
[ "greedy", "implementation" ]
null
null
The All-Berland National Olympiad in Informatics has just ended! Now Vladimir wants to upload the contest from the Olympiad as a gym to a popular Codehorses website. Unfortunately, the archive with Olympiad's data is a mess. For example, the files with tests are named arbitrary without any logic. Vladimir wants to re...
The first line contains single integer *n* (1<=≤<=*n*<=≤<=105) — the number of files with tests. *n* lines follow, each describing a file with test. Each line has a form of "name_i type_i", where "name_i" is the filename, and "type_i" equals "1", if the *i*-th file contains an example test, and "0" if it contains a re...
In the first line print the minimum number of lines in Vladimir's script file. After that print the script file, each line should be "move file_1 file_2", where "file_1" is an existing at the moment of this line being run filename, and "file_2" — is a string of digits and small English letters with length from 1 to 6.
[ "5\n01 0\n2 1\n2extra 0\n3 1\n99 0\n", "2\n1 0\n2 1\n", "5\n1 0\n11 1\n111 0\n1111 1\n11111 0\n" ]
[ "4\nmove 3 1\nmove 01 5\nmove 2extra 4\nmove 99 3\n", "3\nmove 1 3\nmove 2 1\nmove 3 2", "5\nmove 1 5\nmove 11 1\nmove 1111 2\nmove 111 4\nmove 11111 3\n" ]
none
[ { "input": "5\n01 0\n2 1\n2extra 0\n3 1\n99 0", "output": "4\nmove 3 1\nmove 01 5\nmove 2extra 4\nmove 99 3" }, { "input": "2\n1 0\n2 1", "output": "3\nmove 1 odt0m5\nmove 2 1\nmove odt0m5 2" }, { "input": "5\n1 0\n11 1\n111 0\n1111 1\n11111 0", "output": "5\nmove 1 5\nmove 11 1\nmov...
46
0
0
3,560
818
Multicolored Cars
[ "data structures", "implementation" ]
null
null
Alice and Bob got very bored during a long car trip so they decided to play a game. From the window they can see cars of different colors running past them. Cars are going one after another. The game rules are like this. Firstly Alice chooses some color *A*, then Bob chooses some color *B* (*A*<=≠<=*B*). After each ca...
The first line contains two integer numbers *n* and *A* (1<=≤<=*n*<=≤<=105,<=1<=≤<=*A*<=≤<=106) – number of cars and the color chosen by Alice. The second line contains *n* integer numbers *c*1,<=*c*2,<=...,<=*c**n* (1<=≤<=*c**i*<=≤<=106) — colors of the cars that Alice and Bob will encounter in the order of their app...
Output such color *B* (1<=≤<=*B*<=≤<=106) that if Bob chooses it then he will win the game. If there are multiple solutions, print any of them. If there is no such color then print -1. It is guaranteed that if there exists any solution then there exists solution with (1<=≤<=*B*<=≤<=106).
[ "4 1\n2 1 4 2\n", "5 2\n2 2 4 5 3\n", "3 10\n1 2 3\n" ]
[ "2\n", "-1\n", "4\n" ]
Let's consider availability of colors in the first example: - *cnt*<sub class="lower-index">2</sub>(*i*) ≥ *cnt*<sub class="lower-index">1</sub>(*i*) for every *i*, and color 2 can be the answer. - *cnt*<sub class="lower-index">4</sub>(2) &lt; *cnt*<sub class="lower-index">1</sub>(2), so color 4 isn't the winning o...
[ { "input": "4 1\n2 1 4 2", "output": "2" }, { "input": "5 2\n2 2 4 5 3", "output": "-1" }, { "input": "3 10\n1 2 3", "output": "4" }, { "input": "1 1\n2", "output": "3" }, { "input": "1 2\n2", "output": "-1" }, { "input": "10 6\n8 5 1 6 6 5 10 6 9 8", ...
2,000
9,216,000
0
3,561
899
Shovel Sale
[ "constructive algorithms", "math" ]
null
null
There are *n* shovels in Polycarp's shop. The *i*-th shovel costs *i* burles, that is, the first shovel costs 1 burle, the second shovel costs 2 burles, the third shovel costs 3 burles, and so on. Polycarps wants to sell shovels in pairs. Visitors are more likely to buy a pair of shovels if their total cost ends with ...
The first line contains a single integer *n* (2<=≤<=*n*<=≤<=109) — the number of shovels in Polycarp's shop.
Print the number of pairs of shovels such that their total cost ends with maximum possible number of nines. Note that it is possible that the largest number of 9s at the end is 0, then you should count all such ways. It is guaranteed that for every *n*<=≤<=109 the answer doesn't exceed 2·109.
[ "7\n", "14\n", "50\n" ]
[ "3\n", "9\n", "1\n" ]
In the first example the maximum possible number of nines at the end is one. Polycarp cah choose the following pairs of shovels for that purpose: - 2 and 7; - 3 and 6; - 4 and 5. In the second example the maximum number of nines at the end of total cost of two shovels is one. The following pairs of shovels suit Po...
[ { "input": "7", "output": "3" }, { "input": "14", "output": "9" }, { "input": "50", "output": "1" }, { "input": "999999999", "output": "499999999" }, { "input": "15", "output": "11" }, { "input": "3", "output": "3" }, { "input": "6500", ...
46
0
0
3,563
234
Weather
[ "dp", "implementation" ]
null
null
Scientists say a lot about the problems of global warming and cooling of the Earth. Indeed, such natural phenomena strongly influence all life on our planet. Our hero Vasya is quite concerned about the problems. He decided to try a little experiment and observe how outside daily temperature changes. He hung out a ther...
The first line contains a single integer *n* (2<=≤<=*n*<=≤<=105) — the number of days for which Vasya has been measuring the temperature. The second line contains a sequence of *n* integers *t*1,<=*t*2,<=...,<=*t**n* (|*t**i*|<=≤<=109) — the sequence of temperature values. Numbers *t**i* are separated by single space...
Print a single integer — the answer to the given task.
[ "4\n-1 1 -2 1\n", "5\n0 -1 1 2 -5\n" ]
[ "1\n", "2\n" ]
Note to the first sample: there are two ways to change exactly one number so that the sequence met Vasya's condition. You can either replace the first number 1 by any negative number or replace the number -2 by any positive number.
[ { "input": "4\n-1 1 -2 1", "output": "1" }, { "input": "5\n0 -1 1 2 -5", "output": "2" }, { "input": "6\n0 0 0 0 0 0", "output": "6" }, { "input": "6\n-1 -2 -3 -4 5 6", "output": "0" }, { "input": "8\n1 2 -1 0 10 2 12 13", "output": "3" }, { "input": "...
342
15,872,000
3
3,565
400
Inna and Huge Candy Matrix
[ "implementation", "math" ]
null
null
Inna and Dima decided to surprise Sereja. They brought a really huge candy matrix, it's big even for Sereja! Let's number the rows of the giant matrix from 1 to *n* from top to bottom and the columns — from 1 to *m*, from left to right. We'll represent the cell on the intersection of the *i*-th row and *j*-th column as...
The first line of the input contains fix integers *n*, *m*, *x*, *y*, *z*, *p* (1<=≤<=*n*,<=*m*<=≤<=109; 0<=≤<=*x*,<=*y*,<=*z*<=≤<=109; 1<=≤<=*p*<=≤<=105). Each of the following *p* lines contains two integers *x**k*, *y**k* (1<=≤<=*x**k*<=≤<=*n*; 1<=≤<=*y**k*<=≤<=*m*) — the initial coordinates of the *k*-th candy. Tw...
For each of the *p* candies, print on a single line its space-separated new coordinates.
[ "3 3 3 1 1 9\n1 1\n1 2\n1 3\n2 1\n2 2\n2 3\n3 1\n3 2\n3 3\n" ]
[ "1 3\n1 2\n1 1\n2 3\n2 2\n2 1\n3 3\n3 2\n3 1\n" ]
Just for clarity. Horizontal rotating is like a mirroring of the matrix. For matrix:
[ { "input": "3 3 3 1 1 9\n1 1\n1 2\n1 3\n2 1\n2 2\n2 3\n3 1\n3 2\n3 3", "output": "1 3\n1 2\n1 1\n2 3\n2 2\n2 1\n3 3\n3 2\n3 1" }, { "input": "5 5 0 0 0 1\n1 4", "output": "1 4" }, { "input": "14 76 376219315 550904689 16684615 24\n11 21\n1 65\n5 25\n14 63\n11 30\n1 19\n5 7\n9 51\n2 49\n1...
46
0
0
3,567
0
none
[ "none" ]
null
null
For an array $b$ of length $m$ we define the function $f$ as where $\oplus$ is [bitwise exclusive OR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR). For example, $f(1,2,4,8)=f(1\oplus2,2\oplus4,4\oplus8)=f(3,6,12)=f(3\oplus6,6\oplus12)=f(5,10)=f(5\oplus10)=f(15)=15$ You are given an array $a$ and a few queri...
The first line contains a single integer $n$ ($1 \le n \le 5000$) — the length of $a$. The second line contains $n$ integers $a_1, a_2, \dots, a_n$ ($0 \le a_i \le 2^{30}-1$) — the elements of the array. The third line contains a single integer $q$ ($1 \le q \le 100\,000$) — the number of queries. Each of the next $...
Print $q$ lines — the answers for the queries.
[ "3\n8 4 1\n2\n2 3\n1 2\n", "6\n1 2 4 8 16 32\n4\n1 6\n2 5\n3 4\n1 2\n" ]
[ "5\n12\n", "60\n30\n12\n3\n" ]
In first sample in both queries the maximum value of the function is reached on the subsegment that is equal to the whole segment. In second sample, optimal segment for first query are $[3,6]$, for second query — $[2,5]$, for third — $[3,4]$, for fourth — $[1,2]$.
[ { "input": "3\n8 4 1\n2\n2 3\n1 2", "output": "5\n12" }, { "input": "6\n1 2 4 8 16 32\n4\n1 6\n2 5\n3 4\n1 2", "output": "60\n30\n12\n3" } ]
93
0
0
3,574
817
Imbalanced Array
[ "data structures", "divide and conquer", "dsu", "sortings" ]
null
null
You are given an array *a* consisting of *n* elements. The imbalance value of some subsegment of this array is the difference between the maximum and minimum element from this segment. The imbalance value of the array is the sum of imbalance values of all subsegments of this array. For example, the imbalance value of ...
The first line contains one integer *n* (1<=≤<=*n*<=≤<=106) — size of the array *a*. The second line contains *n* integers *a*1,<=*a*2... *a**n* (1<=≤<=*a**i*<=≤<=106) — elements of the array.
Print one integer — the imbalance value of *a*.
[ "3\n1 4 1\n" ]
[ "9\n" ]
none
[ { "input": "3\n1 4 1", "output": "9" }, { "input": "10\n1 1 1 1 1 1 1 1 1 1", "output": "0" }, { "input": "10\n1 4 4 3 5 2 4 2 4 5", "output": "123" }, { "input": "10\n9 6 8 5 5 2 8 9 2 2", "output": "245" }, { "input": "30\n4 5 2 2 5 2 3 4 3 3 2 1 3 4 4 5 3 3 1 5...
2,000
12,083,200
0
3,599
0
none
[ "none" ]
null
null
One day in the IT lesson Anna and Maria learned about the lexicographic order. String *x* is lexicographically less than string *y*, if either *x* is a prefix of *y* (and *x*<=≠<=*y*), or there exists such *i* (1<=≤<=*i*<=≤<=*min*(|*x*|,<=|*y*|)), that *x**i*<=&lt;<=*y**i*, and for any *j* (1<=≤<=*j*<=&lt;<=*i*) *x**j...
The first line contains a non-empty string that only consists of small Latin letters ("a"-"z"), whose length does not exceed 105. The second line contains the only integer *k* (1<=≤<=*k*<=≤<=105).
Print the string Anna and Maria need — the *k*-th (in the lexicographical order) substring of the given string. If the total number of substrings is less than *k*, print a string saying "No such line." (without the quotes).
[ "aa\n2\n", "abc\n5\n", "abab\n7\n" ]
[ "a\n", "bc\n", "b\n" ]
In the second sample before string "bc" follow strings "a", "ab", "abc", "b".
[ { "input": "aa\n2", "output": "a" }, { "input": "abc\n5", "output": "bc" }, { "input": "abab\n7", "output": "b" }, { "input": "codeforces\n1", "output": "c" }, { "input": "cccc\n8", "output": "ccc" }, { "input": "abcdefghijklmnopqrstuvwxyz\n27", "o...
2,000
15,052,800
0
3,609
290
Greedy Petya
[ "*special", "dfs and similar", "graphs", "greedy" ]
null
null
Petya is an unexperienced programming contestant. Recently he has come across the following problem: You are given a non-directed graph which consists of *n* nodes and *m* edges. Your task is to determine whether the graph contains a Hamiltonian path. Petya wrote a quick bug-free code which he believes solves this pr...
The first line contains two integers *n*,<=*m* (1<=≤<=*n*<=≤<=20; 0<=≤<=*m*<=≤<=400). Next *m* lines contain pairs of integers *v**i*,<=*u**i* (1<=≤<=*v**i*,<=*u**i*<=≤<=*n*).
Follow the format of Petya's code output.
[ "2 3\n1 2\n2 1\n1 1\n", "3 0\n", "10 20\n3 10\n4 6\n4 9\n7 5\n8 8\n3 10\n9 7\n5 2\n9 2\n10 6\n10 4\n1 1\n7 2\n8 4\n7 2\n1 8\n5 4\n10 2\n8 5\n5 2\n" ]
[ "Yes\n", "No\n", "No\n" ]
none
[]
62
0
0
3,619
1,003
Binary String Constructing
[ "constructive algorithms" ]
null
null
You are given three integers $a$, $b$ and $x$. Your task is to construct a binary string $s$ of length $n = a + b$ such that there are exactly $a$ zeroes, exactly $b$ ones and exactly $x$ indices $i$ (where $1 \le i &lt; n$) such that $s_i \ne s_{i + 1}$. It is guaranteed that the answer always exists. For example, fo...
The first line of the input contains three integers $a$, $b$ and $x$ ($1 \le a, b \le 100, 1 \le x &lt; a + b)$.
Print only one string $s$, where $s$ is any binary string satisfying conditions described above. It is guaranteed that the answer always exists.
[ "2 2 1\n", "3 3 3\n", "5 3 6\n" ]
[ "1100\n", "101100\n", "01010100\n" ]
All possible answers for the first example: - 1100; - 0011. All possible answers for the second example: - 110100; - 101100; - 110010; - 100110; - 011001; - 001101; - 010011; - 001011.
[ { "input": "2 2 1", "output": "1100" }, { "input": "3 3 3", "output": "101100" }, { "input": "5 3 6", "output": "01010100" }, { "input": "100 1 2", "output": "01000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000" }, { ...
327
30,208,000
0
3,628
300
Coach
[ "brute force", "dfs and similar", "graphs" ]
null
null
A programming coach has *n* students to teach. We know that *n* is divisible by 3. Let's assume that all students are numbered from 1 to *n*, inclusive. Before the university programming championship the coach wants to split all students into groups of three. For some pairs of students we know that they want to be on ...
The first line of the input contains integers *n* and *m* (3<=≤<=*n*<=≤<=48, . Then follow *m* lines, each contains a pair of integers *a**i*,<=*b**i* (1<=≤<=*a**i*<=&lt;<=*b**i*<=≤<=*n*) — the pair *a**i*,<=*b**i* means that students with numbers *a**i* and *b**i* want to be on the same team. It is guaranteed that *n...
If the required division into teams doesn't exist, print number -1. Otherwise, print lines. In each line print three integers *x**i*, *y**i*, *z**i* (1<=≤<=*x**i*,<=*y**i*,<=*z**i*<=≤<=*n*) — the *i*-th team. If there are multiple answers, you are allowed to print any of them.
[ "3 0\n", "6 4\n1 2\n2 3\n3 4\n5 6\n", "3 3\n1 2\n2 3\n1 3\n" ]
[ "3 2 1 \n", "-1\n", "3 2 1 \n" ]
none
[ { "input": "3 0", "output": "3 2 1 " }, { "input": "6 4\n1 2\n2 3\n3 4\n5 6", "output": "-1" }, { "input": "3 3\n1 2\n2 3\n1 3", "output": "3 2 1 " }, { "input": "6 3\n1 2\n3 4\n5 6", "output": "-1" }, { "input": "15 9\n1 4\n1 6\n2 7\n2 11\n4 6\n5 12\n7 11\n9 14\n...
62
0
-1
3,630
613
Peter and Snow Blower
[ "binary search", "geometry", "ternary search" ]
null
null
Peter got a new snow blower as a New Year present. Of course, Peter decided to try it immediately. After reading the instructions he realized that it does not work like regular snow blowing machines. In order to make it work, you need to tie it to some point that it does not cover, and then switch it on. As a result it...
The first line of the input contains three integers — the number of vertices of the polygon *n* (), and coordinates of point *P*. Each of the next *n* lines contains two integers — coordinates of the vertices of the polygon in the clockwise or counterclockwise order. It is guaranteed that no three consecutive vertices...
Print a single real value number — the area of the region that will be cleared. Your answer will be considered correct if its absolute or relative error does not exceed 10<=-<=6. Namely: let's assume that your answer is *a*, and the answer of the jury is *b*. The checker program will consider your answer correct, if ...
[ "3 0 0\n0 1\n-1 2\n1 2\n", "4 1 -1\n0 0\n1 2\n2 0\n1 1\n" ]
[ "12.566370614359172464\n", "21.991148575128551812\n" ]
In the first sample snow will be removed from that area:
[ { "input": "3 0 0\n0 1\n-1 2\n1 2", "output": "12.566370614359172464" }, { "input": "4 1 -1\n0 0\n1 2\n2 0\n1 1", "output": "21.991148575128551812" }, { "input": "3 0 0\n-1 1\n0 3\n1 1", "output": "25.132741228718344928" }, { "input": "3 -4 2\n-3 2\n5 -5\n5 3", "output": ...
46
0
0
3,642
440
Balancer
[ "greedy", "implementation" ]
null
null
Petya has *k* matches, placed in *n* matchboxes lying in a line from left to right. We know that *k* is divisible by *n*. Petya wants all boxes to have the same number of matches inside. For that, he can move a match from its box to the adjacent one in one move. How many such moves does he need to achieve the desired c...
The first line contains integer *n* (1<=≤<=*n*<=≤<=50000). The second line contains *n* non-negative numbers that do not exceed 109, the *i*-th written number is the number of matches in the *i*-th matchbox. It is guaranteed that the total number of matches is divisible by *n*.
Print the total minimum number of moves.
[ "6\n1 6 2 5 3 7\n" ]
[ "12\n" ]
none
[ { "input": "6\n1 6 2 5 3 7", "output": "12" }, { "input": "6\n6 6 6 0 0 0", "output": "27" }, { "input": "6\n0 0 0 6 6 6", "output": "27" }, { "input": "6\n6 6 0 0 6 6", "output": "12" }, { "input": "5\n0 0 0 0 0", "output": "0" }, { "input": "10\n0 10...
500
921,600
0
3,646
452
Magic Trick
[ "combinatorics", "math", "probabilities" ]
null
null
Alex enjoys performing magic tricks. He has a trick that requires a deck of *n* cards. He has *m* identical decks of *n* different cards each, which have been mixed together. When Alex wishes to perform the trick, he grabs *n* cards at random and performs the trick with those. The resulting deck looks like a normal dec...
First line of the input consists of two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=1000), separated by space — number of cards in each deck, and number of decks.
On the only line of the output print one floating point number – probability of Alex successfully performing the trick. Relative or absolute error of your answer should not be higher than 10<=-<=6.
[ "2 2\n", "4 4\n", "1 2\n" ]
[ "0.6666666666666666\n", "0.4000000000000000\n", "1.0000000000000000\n" ]
In the first sample, with probability <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/64c94d13eeb330b494061e86538db66574ad0f7d.png" style="max-width: 100.0%;max-height: 100.0%;"/> Alex will perform the trick with two cards with the same value from two different decks. In this case the trick...
[ { "input": "2 2", "output": "0.6666666666666666" }, { "input": "4 4", "output": "0.4000000000000000" }, { "input": "1 2", "output": "1.0000000000000000" }, { "input": "2 1", "output": "0.5000000000000000" }, { "input": "10 10", "output": "0.1818181818181818" ...
155
1,638,400
3
3,648
851
Arpa and an exam about geometry
[ "geometry", "math" ]
null
null
Arpa is taking a geometry exam. Here is the last problem of the exam. You are given three points *a*,<=*b*,<=*c*. Find a point and an angle such that if we rotate the page around the point by the angle, the new position of *a* is the same as the old position of *b*, and the new position of *b* is the same as the old ...
The only line contains six integers *a**x*,<=*a**y*,<=*b**x*,<=*b**y*,<=*c**x*,<=*c**y* (|*a**x*|,<=|*a**y*|,<=|*b**x*|,<=|*b**y*|,<=|*c**x*|,<=|*c**y*|<=≤<=109). It's guaranteed that the points are distinct.
Print "Yes" if the problem has a solution, "No" otherwise. You can print each letter in any case (upper or lower).
[ "0 1 1 1 1 0\n", "1 1 0 0 1000 1000\n" ]
[ "Yes\n", "No\n" ]
In the first sample test, rotate the page around (0.5, 0.5) by <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/9d845923f4d356a48d8ede337db0303821311f0c.png" style="max-width: 100.0%;max-height: 100.0%;"/>. In the second sample test, you can't find any solution.
[ { "input": "0 1 1 1 1 0", "output": "Yes" }, { "input": "1 1 0 0 1000 1000", "output": "No" }, { "input": "1 0 2 0 3 0", "output": "No" }, { "input": "3 4 0 0 4 3", "output": "Yes" }, { "input": "-1000000000 1 0 0 1000000000 1", "output": "Yes" }, { "i...
61
5,529,600
0
3,660
920
SUM and REPLACE
[ "brute force", "data structures", "dsu", "number theory" ]
null
null
Let *D*(*x*) be the number of positive divisors of a positive integer *x*. For example, *D*(2)<==<=2 (2 is divisible by 1 and 2), *D*(6)<==<=4 (6 is divisible by 1, 2, 3 and 6). You are given an array *a* of *n* integers. You have to process two types of queries: 1. REPLACE *l* *r* — for every replace *a**i* with *...
The first line contains two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=3·105) — the number of elements in the array and the number of queries to process, respectively. The second line contains *n* integers *a*1, *a*2, ..., *a**n* (1<=≤<=*a**i*<=≤<=106) — the elements of the array. Then *m* lines follow, each containin...
For each SUM query print the answer to it.
[ "7 6\n6 4 1 10 3 2 4\n2 1 7\n2 4 5\n1 3 5\n2 4 4\n1 5 7\n2 1 7\n" ]
[ "30\n13\n4\n22\n" ]
none
[ { "input": "7 6\n6 4 1 10 3 2 4\n2 1 7\n2 4 5\n1 3 5\n2 4 4\n1 5 7\n2 1 7", "output": "30\n13\n4\n22" }, { "input": "4 2\n1 1 1 3\n1 1 4\n2 1 4", "output": "5" }, { "input": "10 2\n1 1 1 1 1 1 1 1 1 9\n1 1 10\n2 1 10", "output": "12" }, { "input": "4 2\n1 1 3 1\n1 1 4\n2 1 4"...
2,000
19,558,400
0
3,673
665
Buses Between Cities
[ "implementation" ]
null
null
Buses run between the cities *A* and *B*, the first one is at 05:00 AM and the last one departs not later than at 11:59 PM. A bus from the city *A* departs every *a* minutes and arrives to the city *B* in a *t**a* minutes, and a bus from the city *B* departs every *b* minutes and arrives to the city *A* in a *t**b* min...
The first line contains two integers *a*,<=*t**a* (1<=≤<=*a*,<=*t**a*<=≤<=120) — the frequency of the buses from the city *A* to the city *B* and the travel time. Both values are given in minutes. The second line contains two integers *b*,<=*t**b* (1<=≤<=*b*,<=*t**b*<=≤<=120) — the frequency of the buses from the city...
Print the only integer *z* — the number of buses Simion will meet on the way. Note that you should not count the encounters in cities *A* and *B*.
[ "10 30\n10 35\n05:20\n", "60 120\n24 100\n13:00\n" ]
[ "5\n", "9\n" ]
In the first example Simion departs form the city *A* at 05:20 AM and arrives to the city *B* at 05:50 AM. He will meet the first 5 buses from the city *B* that departed in the period [05:00 AM - 05:40 AM]. Also Simion will meet a bus in the city *B* at 05:50 AM, but he will not count it. Also note that the first enco...
[ { "input": "10 30\n10 35\n05:20", "output": "5" }, { "input": "60 120\n24 100\n13:00", "output": "9" }, { "input": "30 60\n60 60\n22:30", "output": "2" }, { "input": "30 60\n10 60\n23:30", "output": "8" }, { "input": "5 45\n4 60\n21:00", "output": "26" }, ...
186
23,244,800
3
3,674
412
Pattern
[ "implementation", "strings" ]
null
null
Developers often face with regular expression patterns. A pattern is usually defined as a string consisting of characters and metacharacters that sets the rules for your search. These patterns are most often used to check whether a particular string meets the certain rules. In this task, a pattern will be a string con...
The first line contains a single integer *n* (1<=≤<=*n*<=≤<=105) — the number of patterns. Next *n* lines contain the patterns. It is guaranteed that the patterns can only consist of small English letters and symbols '?'. All patterns are non-empty and have the same length. The total length of all the patterns does no...
In a single line print the answer to the problem — the pattern with the minimal number of signs '?', which intersects with each of the given ones. If there are several answers, print any of them.
[ "2\n?ab\n??b\n", "2\na\nb\n", "1\n?a?b\n" ]
[ "xab\n", "?\n", "cacb\n" ]
Consider the first example. Pattern xab intersects with each of the given patterns. Pattern ??? also intersects with each of the given patterns, but it contains more question signs, hence it is not an optimal answer. Clearly, xab is the optimal answer, because it doesn't contain any question sign. There are a lot of ot...
[ { "input": "2\n?ab\n??b", "output": "xab" }, { "input": "2\na\nb", "output": "?" }, { "input": "1\n?a?b", "output": "cacb" }, { "input": "1\n?", "output": "x" }, { "input": "3\nabacaba\nabacaba\nabacaba", "output": "abacaba" }, { "input": "3\nabc?t\n?b...
218
4,198,400
3
3,678
312
Whose sentence is it?
[ "implementation", "strings" ]
null
null
One day, liouzhou_101 got a chat record of Freda and Rainbow. Out of curiosity, he wanted to know which sentences were said by Freda, and which were said by Rainbow. According to his experience, he thought that Freda always said "lala." at the end of her sentences, while Rainbow always said "miao." at the beginning of ...
The first line of the input contains an integer *n* (1<=≤<=*n*<=≤<=10), number of sentences in the chat record. Each of the next *n* lines contains a sentence. A sentence is a string that contains only Latin letters (A-Z, a-z), underline (_), comma (,), point (.) and space ( ). Its length doesn’t exceed 100.
For each sentence, output "Freda's" if the sentence was said by Freda, "Rainbow's" if the sentence was said by Rainbow, or "OMG&gt;.&lt; I don't know!" if liouzhou_101 can’t recognize whose sentence it is. He can’t recognize a sentence if it begins with "miao." and ends with "lala.", or satisfies neither of the conditi...
[ "5\nI will go to play with you lala.\nwow, welcome.\nmiao.lala.\nmiao.\nmiao .\n" ]
[ "Freda's\nOMG&gt;.&lt; I don't know!\nOMG&gt;.&lt; I don't know!\nRainbow's\nOMG&gt;.&lt; I don't know!\n" ]
none
[ { "input": "5\nI will go to play with you lala.\nwow, welcome.\nmiao.lala.\nmiao.\nmiao .", "output": "Freda's\nOMG>.< I don't know!\nOMG>.< I don't know!\nRainbow's\nOMG>.< I don't know!" }, { "input": "10\nLpAEKiHVJrzSZqBVSSyY\nYECGBlala.\nUZeGpeM.UCwiHmmA\nqt_,.b_.LSwJtJ.\nFAnXZtHlala.\nmiao.iape...
124
2,048,000
-1
3,681
932
Palindromic Supersequence
[ "constructive algorithms" ]
null
null
You are given a string *A*. Find a string *B*, where *B* is a palindrome and *A* is a subsequence of *B*. A subsequence of a string is a string that can be derived from it by deleting some (not necessarily consecutive) characters without changing the order of the remaining characters. For example, "cotst" is a subsequ...
First line contains a string *A* (1<=≤<=|*A*|<=≤<=103) consisting of lowercase Latin letters, where |*A*| is a length of *A*.
Output single line containing *B* consisting of only lowercase Latin letters. You do not need to find the shortest answer, the only restriction is that the length of string *B* should not exceed 104. If there are many possible *B*, print any of them.
[ "aba\n", "ab\n" ]
[ "aba", "aabaa" ]
In the first example, "aba" is a subsequence of "aba" which is a palindrome. In the second example, "ab" is a subsequence of "aabaa" which is a palindrome.
[ { "input": "aba", "output": "abaaba" }, { "input": "ab", "output": "abba" }, { "input": "krnyoixirslfszfqivgkaflgkctvbvksipwomqxlyqxhlbceuhbjbfnhofcgpgwdseffycthmlpcqejgskwjkbkbbmifnurnwyhevsoqzmtvzgfiqajfrgyuzxnrtxectcnlyoisbglpdbjbslxlpoymrcxmdtqhcnlvtqdwftuzgbdxsyscwbrguostbelnvtaqdmk...
77
5,632,000
3
3,694
670
Game of Robots
[ "implementation" ]
null
null
In late autumn evening *n* robots gathered in the cheerful company of friends. Each robot has a unique identifier — an integer from 1 to 109. At some moment, robots decided to play the game "Snowball". Below there are the rules of this game. First, all robots stand in a row. Then the first robot says his identifier. A...
The first line contains two positive integers *n* and *k* (1<=≤<=*n*<=≤<=100<=000, 1<=≤<=*k*<=≤<=*min*(2·109,<=*n*·(*n*<=+<=1)<=/<=2). The second line contains the sequence *id*1,<=*id*2,<=...,<=*id**n* (1<=≤<=*id**i*<=≤<=109) — identifiers of roborts. It is guaranteed that all identifiers are different.
Print the *k*-th pronounced identifier (assume that the numeration starts from 1).
[ "2 2\n1 2\n", "4 5\n10 4 18 3\n" ]
[ "1\n", "4\n" ]
In the first sample identifiers of robots will be pronounced in the following order: 1, 1, 2. As *k* = 2, the answer equals to 1. In the second test case identifiers of robots will be pronounced in the following order: 10, 10, 4, 10, 4, 18, 10, 4, 18, 3. As *k* = 5, the answer equals to 4.
[ { "input": "2 2\n1 2", "output": "1" }, { "input": "4 5\n10 4 18 3", "output": "4" }, { "input": "1 1\n4", "output": "4" }, { "input": "2 1\n5 1", "output": "5" }, { "input": "2 2\n1 4", "output": "1" }, { "input": "2 3\n6 7", "output": "7" }, ...
1,013
268,390,400
0
3,695
644
Hostname Aliases
[ "*special", "binary search", "data structures", "implementation", "sortings", "strings" ]
null
null
There are some websites that are accessible through several different addresses. For example, for a long time Codeforces was accessible with two hostnames codeforces.com and codeforces.ru. You are given a list of page addresses being queried. For simplicity we consider all addresses to have the form http://&lt;hostnam...
The first line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=100<=000) — the number of page queries. Then follow *n* lines each containing exactly one address. Each address is of the form http://&lt;hostname&gt;[/&lt;path&gt;], where: - &lt;hostname&gt; consists of lowercase English letters and dots, ther...
First print *k* — the number of groups of server names that correspond to one website. You should count only groups of size greater than one. Next *k* lines should contain the description of groups, one group per line. For each group print all server names separated by a single space. You are allowed to print both gro...
[ "10\nhttp://abacaba.ru/test\nhttp://abacaba.ru/\nhttp://abacaba.com\nhttp://abacaba.com/test\nhttp://abacaba.de/\nhttp://abacaba.ru/test\nhttp://abacaba.de/test\nhttp://abacaba.com/\nhttp://abacaba.com/t\nhttp://abacaba.com/test\n", "14\nhttp://c\nhttp://ccc.bbbb/aba..b\nhttp://cba.com\nhttp://a.c/aba..b/a\nhttp:...
[ "1\nhttp://abacaba.de http://abacaba.ru \n", "2\nhttp://cba.com http://ccc.bbbb \nhttp://a.a.a http://a.c http://abc \n" ]
none
[ { "input": "10\nhttp://abacaba.ru/test\nhttp://abacaba.ru/\nhttp://abacaba.com\nhttp://abacaba.com/test\nhttp://abacaba.de/\nhttp://abacaba.ru/test\nhttp://abacaba.de/test\nhttp://abacaba.com/\nhttp://abacaba.com/t\nhttp://abacaba.com/test", "output": "1\nhttp://abacaba.de http://abacaba.ru " }, { "...
0
0
-1
3,703
0
none
[ "none" ]
null
null
A couple of friends, Axel and Marston are travelling across the country of Bitland. There are *n* towns in Bitland, with some pairs of towns connected by one-directional roads. Each road in Bitland is either a pedestrian road or a bike road. There can be multiple roads between any pair of towns, and may even be a road ...
The first line contains two integers *n* and *m* (1<=≤<=*n*<=≤<=500, 0<=≤<=*m*<=≤<=2*n*2) — the number of towns and roads in Bitland respectively. Next *m* lines describe the roads. *i*-th of these lines contains three integers *v**i*, *u**i* and *t**i* (1<=≤<=*v**i*,<=*u**i*<=≤<=*n*, 0<=≤<=*t**i*<=≤<=1), where *v**i*...
If it is possible to find a route with length strictly greater than 1018, print -1. Otherwise, print the maximum length of a suitable path.
[ "2 2\n1 2 0\n2 2 1\n", "2 3\n1 2 0\n2 2 1\n2 2 0\n" ]
[ "3\n", "-1\n" ]
In the first sample we can obtain a route of length 3 by travelling along the road 1 from town 1 to town 2, and then following the road 2 twice from town 2 to itself. In the second sample we can obtain an arbitrarily long route by travelling the road 1 first, and then choosing road 2 or 3 depending on the necessary ty...
[]
0
0
-1
3,729
63
Settlers' Training
[ "implementation" ]
B. Settlers' Training
2
256
In a strategic computer game "Settlers II" one has to build defense structures to expand and protect the territory. Let's take one of these buildings. At the moment the defense structure accommodates exactly *n* soldiers. Within this task we can assume that the number of soldiers in the defense structure won't either i...
The first line contains two integers *n* and *k* (1<=≤<=*n*,<=*k*<=≤<=100). They represent the number of soldiers and the number of different ranks correspondingly. The second line contains *n* numbers in the non-decreasing order. The *i*-th of them, *a**i*, represents the rank of the *i*-th soldier in the defense buil...
Print a single integer — the number of golden coins needed to raise all the soldiers to the maximal rank.
[ "4 4\n1 2 2 3\n", "4 3\n1 1 1 1\n" ]
[ "4", "5" ]
In the first example the ranks will be raised in the following manner: 1 2 2 3  →  2 2 3 4  →  2 3 4 4  →  3 4 4 4  →  4 4 4 4 Thus totals to 4 training sessions that require 4 golden coins.
[ { "input": "4 4\n1 2 2 3", "output": "4" }, { "input": "4 3\n1 1 1 1", "output": "5" }, { "input": "3 3\n1 2 3", "output": "2" }, { "input": "1 1\n1", "output": "0" }, { "input": "1 5\n1", "output": "4" }, { "input": "1 5\n4", "output": "1" }, ...
124
102,400
3.968809
3,736
769
Year of University Entrance
[ "*special", "implementation", "sortings" ]
null
null
There is the faculty of Computer Science in Berland. In the social net "TheContact!" for each course of this faculty there is the special group whose name equals the year of university entrance of corresponding course of students at the university. Each of students joins the group of his course and joins all groups f...
The first line contains the positive odd integer *n* (1<=≤<=*n*<=≤<=5) — the number of groups which Igor joined. The next line contains *n* distinct integers *a*1,<=*a*2,<=...,<=*a**n* (2010<=≤<=*a**i*<=≤<=2100) — years of student's university entrance for each group in which Igor is the member. It is guaranteed tha...
Print the year of Igor's university entrance.
[ "3\n2014 2016 2015\n", "1\n2050\n" ]
[ "2015\n", "2050\n" ]
In the first test the value *x* = 1. Igor entered the university in 2015. So he joined groups members of which are students who entered the university in 2014, 2015 and 2016. In the second test the value *x* = 0. Igor entered only the group which corresponds to the year of his university entrance.
[ { "input": "3\n2014 2016 2015", "output": "2015" }, { "input": "1\n2050", "output": "2050" }, { "input": "1\n2010", "output": "2010" }, { "input": "1\n2011", "output": "2011" }, { "input": "3\n2010 2011 2012", "output": "2011" }, { "input": "3\n2049 20...
46
4,300,800
3
3,740
980
The Number Games
[ "data structures", "greedy", "trees" ]
null
null
The nation of Panel holds an annual show called The Number Games, where each district in the nation will be represented by one contestant. The nation has $n$ districts numbered from $1$ to $n$, each district has exactly one path connecting it to every other district. The number of fans of a contestant from district $i...
The first line of input contains two integers $n$ and $k$ ($1 \leq k &lt; n \leq 10^6$) — the number of districts in Panel, and the number of contestants the president wishes to remove, respectively. The next $n-1$ lines each contains two integers $a$ and $b$ ($1 \leq a, b \leq n$, $a \ne b$), that describe a road tha...
Print $k$ space-separated integers: the numbers of the districts of which the contestants should be removed, in increasing order of district number.
[ "6 3\n2 1\n2 6\n4 2\n5 6\n2 3\n", "8 4\n2 6\n2 7\n7 8\n1 2\n3 1\n2 4\n7 5\n" ]
[ "1 3 4\n", "1 3 4 5\n" ]
In the first sample, the maximum possible total number of fans is $2^2 + 2^5 + 2^6 = 100$. We can achieve it by removing the contestants of the districts 1, 3, and 4.
[ { "input": "6 3\n2 1\n2 6\n4 2\n5 6\n2 3", "output": "1 3 4" }, { "input": "8 4\n2 6\n2 7\n7 8\n1 2\n3 1\n2 4\n7 5", "output": "1 3 4 5" }, { "input": "2 1\n1 2", "output": "1" }, { "input": "3 1\n2 1\n2 3", "output": "1" }, { "input": "3 2\n1 3\n1 2", "output...
140
20,172,800
0
3,743
645
Mischievous Mess Makers
[ "greedy", "math" ]
null
null
It is a balmy spring afternoon, and Farmer John's *n* cows are ruminating about link-cut cacti in their stalls. The cows, labeled 1 through *n*, are arranged so that the *i*-th cow occupies the *i*-th stall from the left. However, Elsie, after realizing that she will forever live in the shadows beyond Bessie's limeligh...
The first line of the input contains two integers *n* and *k* (1<=≤<=*n*,<=*k*<=≤<=100<=000) — the number of cows and the length of Farmer John's nap, respectively.
Output a single integer, the maximum messiness that the Mischievous Mess Makers can achieve by performing no more than *k* swaps.
[ "5 2\n", "1 10\n" ]
[ "10\n", "0\n" ]
In the first sample, the Mischievous Mess Makers can swap the cows in the stalls 1 and 5 during the first minute, then the cows in stalls 2 and 4 during the second minute. This reverses the arrangement of cows, giving us a total messiness of 10. In the second sample, there is only one cow, so the maximum possible mess...
[ { "input": "5 2", "output": "10" }, { "input": "1 10", "output": "0" }, { "input": "100000 2", "output": "399990" }, { "input": "1 1", "output": "0" }, { "input": "8 3", "output": "27" }, { "input": "7 1", "output": "11" }, { "input": "1000...
62
1,331,200
3
3,749
174
Problem About Equation
[ "math" ]
null
null
A group of *n* merry programmers celebrate Robert Floyd's birthday. Polucarpus has got an honourable task of pouring Ber-Cola to everybody. Pouring the same amount of Ber-Cola to everybody is really important. In other words, the drink's volume in each of the *n* mugs must be the same. Polycarpus has already began the...
The first line contains a pair of integers *n*, *b* (2<=≤<=*n*<=≤<=100,<=1<=≤<=*b*<=≤<=100), where *n* is the total number of friends in the group and *b* is the current volume of drink in the bottle. The second line contains a sequence of integers *a*1,<=*a*2,<=...,<=*a**n* (0<=≤<=*a**i*<=≤<=100), where *a**i* is the ...
Print a single number "-1" (without the quotes), if there is no solution. Otherwise, print *n* float numbers *c*1,<=*c*2,<=...,<=*c**n*, where *c**i* is the volume of the drink to add in the *i*-th mug. Print the numbers with no less than 6 digits after the decimal point, print each *c**i* on a single line. Polycarpus ...
[ "5 50\n1 2 3 4 5\n", "2 2\n1 100\n" ]
[ "12.000000\n11.000000\n10.000000\n9.000000\n8.000000\n", "-1\n" ]
none
[ { "input": "5 50\n1 2 3 4 5", "output": "12.000000\n11.000000\n10.000000\n9.000000\n8.000000" }, { "input": "2 2\n1 100", "output": "-1" }, { "input": "2 2\n1 1", "output": "1.000000\n1.000000" }, { "input": "3 2\n1 2 1", "output": "1.000000\n0.000000\n1.000000" }, { ...
248
6,758,400
3
3,756
630
Lucky Numbers
[ "combinatorics", "math" ]
null
null
The numbers of all offices in the new building of the Tax Office of IT City will have lucky numbers. Lucky number is a number that consists of digits 7 and 8 only. Find the maximum number of offices in the new building of the Tax Office given that a door-plate can hold a number not longer than *n* digits.
The only line of input contains one integer *n* (1<=≤<=*n*<=≤<=55) — the maximum length of a number that a door-plate can hold.
Output one integer — the maximum number of offices, than can have unique lucky numbers not longer than *n* digits.
[ "2\n" ]
[ "6" ]
none
[ { "input": "2", "output": "6" }, { "input": "1", "output": "2" }, { "input": "3", "output": "14" }, { "input": "5", "output": "62" }, { "input": "12", "output": "8190" }, { "input": "34", "output": "34359738366" }, { "input": "43", "out...
31
0
3
3,762
474
Worms
[ "binary search", "implementation" ]
null
null
It is lunch time for Mole. His friend, Marmot, prepared him a nice game for lunch. Marmot brought Mole *n* ordered piles of worms such that *i*-th pile contains *a**i* worms. He labeled all these worms with consecutive integers: worms in first pile are labeled with numbers 1 to *a*1, worms in second pile are labeled w...
The first line contains a single integer *n* (1<=≤<=*n*<=≤<=105), the number of piles. The second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=103, *a*1<=+<=*a*2<=+<=...<=+<=*a**n*<=≤<=106), where *a**i* is the number of worms in the *i*-th pile. The third line contains single integer *m* (...
Print *m* lines to the standard output. The *i*-th line should contain an integer, representing the number of the pile where the worm labeled with the number *q**i* is.
[ "5\n2 7 3 4 9\n3\n1 25 11\n" ]
[ "1\n5\n3\n" ]
For the sample input: - The worms with labels from [1, 2] are in the first pile. - The worms with labels from [3, 9] are in the second pile. - The worms with labels from [10, 12] are in the third pile. - The worms with labels from [13, 16] are in the fourth pile. - The worms with labels from [17, 25] are in the f...
[ { "input": "5\n2 7 3 4 9\n3\n1 25 11", "output": "1\n5\n3" } ]
77
2,355,200
0
3,772
908
New Year and Entity Enumeration
[ "bitmasks", "combinatorics", "dp", "math" ]
null
null
You are given an integer *m*. Let *M*<==<=2*m*<=-<=1. You are also given a set of *n* integers denoted as the set *T*. The integers will be provided in base 2 as *n* binary strings of length *m*. A set of integers *S* is called "good" if the following hold. 1. If , then . 1. If , then 1. 1. All elements of *...
The first line will contain two integers *m* and *n* (1<=≤<=*m*<=≤<=1<=000, 1<=≤<=*n*<=≤<=*min*(2*m*,<=50)). The next *n* lines will contain the elements of *T*. Each line will contain exactly *m* zeros and ones. Elements of *T* will be distinct.
Print a single integer, the number of good sets modulo 109<=+<=7.
[ "5 3\n11010\n00101\n11000\n", "30 2\n010101010101010010101010101010\n110110110110110011011011011011\n" ]
[ "4\n", "860616440\n" ]
An example of a valid set *S* is {00000, 00101, 00010, 00111, 11000, 11010, 11101, 11111}.
[ { "input": "5 3\n11010\n00101\n11000", "output": "4" }, { "input": "30 2\n010101010101010010101010101010\n110110110110110011011011011011", "output": "860616440" }, { "input": "30 10\n001000000011000111000010010000\n000001100001010000000000000100\n000110100010100000000000101000\n110000010...
608
13,107,200
3
3,775
131
Opposites Attract
[ "implementation", "math" ]
null
null
Everybody knows that opposites attract. That is the key principle of the "Perfect Matching" dating agency. The "Perfect Matching" matchmakers have classified each registered customer by his interests and assigned to the *i*-th client number *t**i* (<=-<=10<=≤<=*t**i*<=≤<=10). Of course, one number can be assigned to an...
The first line of the input data contains an integer *n* (1<=≤<=*n*<=≤<=105) which represents the number of registered clients of the "Couple Matching". The second line contains a sequence of integers *t*1,<=*t*2,<=...,<=*t**n* (<=-<=10<=≤<=*t**i*<=≤<=10), *t**i* — is the parameter of the *i*-th customer that has been ...
Print the number of couples of customs with opposite *t*. The opposite number for *x* is number <=-<=*x* (0 is opposite to itself). Couples that only differ in the clients' order are considered the same. Note that the answer to the problem can be large enough, so you must use the 64-bit integer type for calculations. ...
[ "5\n-3 3 0 0 3\n", "3\n0 0 0\n" ]
[ "3\n", "3\n" ]
In the first sample the couples of opposite clients are: (1,2), (1,5) и (3,4). In the second sample any couple of clients is opposite.
[ { "input": "5\n-3 3 0 0 3", "output": "3" }, { "input": "3\n0 0 0", "output": "3" }, { "input": "1\n0", "output": "0" }, { "input": "1\n5", "output": "0" }, { "input": "2\n0 0", "output": "1" }, { "input": "2\n-3 3", "output": "1" }, { "inp...
122
0
0
3,788
350
TL
[ "brute force", "greedy", "implementation" ]
null
null
Valera wanted to prepare a Codesecrof round. He's already got one problem and he wants to set a time limit (TL) on it. Valera has written *n* correct solutions. For each correct solution, he knows its running time (in seconds). Valera has also wrote *m* wrong solutions and for each wrong solution he knows its running ...
The first line contains two integers *n*, *m* (1<=≤<=*n*,<=*m*<=≤<=100). The second line contains *n* space-separated positive integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=100) — the running time of each of the *n* correct solutions in seconds. The third line contains *m* space-separated positive integers *b*1...
If there is a valid TL value, print it. Otherwise, print -1.
[ "3 6\n4 5 2\n8 9 6 10 7 11\n", "3 1\n3 4 5\n6\n" ]
[ "5", "-1\n" ]
none
[ { "input": "3 6\n4 5 2\n8 9 6 10 7 11", "output": "5" }, { "input": "3 1\n3 4 5\n6", "output": "-1" }, { "input": "2 5\n45 99\n49 41 77 83 45", "output": "-1" }, { "input": "50 50\n18 13 5 34 10 36 36 12 15 11 16 17 14 36 23 45 32 24 31 18 24 32 7 1 31 3 49 8 16 23 3 39 47 43...
310
0
0
3,792
160
Find Pair
[ "implementation", "math", "sortings" ]
null
null
You've got another problem dealing with arrays. Let's consider an arbitrary sequence containing *n* (not necessarily different) integers *a*1, *a*2, ..., *a**n*. We are interested in all possible pairs of numbers (*a**i*, *a**j*), (1<=≤<=*i*,<=*j*<=≤<=*n*). In other words, let's consider all *n*2 pairs of numbers, pick...
The first line contains two integers *n* and *k* (1<=≤<=*n*<=≤<=105,<=1<=≤<=*k*<=≤<=*n*2). The second line contains the array containing *n* integers *a*1, *a*2, ..., *a**n* (<=-<=109<=≤<=*a**i*<=≤<=109). The numbers in the array can coincide. All numbers are separated with spaces. Please do not use the %lld specifica...
In the single line print two numbers — the sought *k*-th pair.
[ "2 4\n2 1\n", "3 2\n3 1 5\n" ]
[ "2 2\n", "1 3\n" ]
In the first sample the sorted sequence for the given array looks as: (1, 1), (1, 2), (2, 1), (2, 2). The 4-th of them is pair (2, 2). The sorted sequence for the array from the second sample is given in the statement. The 2-nd pair there is (1, 3).
[ { "input": "2 4\n2 1", "output": "2 2" }, { "input": "3 2\n3 1 5", "output": "1 3" }, { "input": "3 3\n1 1 2", "output": "1 1" }, { "input": "1 1\n-4", "output": "-4 -4" }, { "input": "3 7\n5 4 3", "output": "5 3" }, { "input": "3 6\n10 1 3", "outp...
1,000
179,916,800
0
3,795
765
Code obfuscation
[ "greedy", "implementation", "strings" ]
null
null
Kostya likes Codeforces contests very much. However, he is very disappointed that his solutions are frequently hacked. That's why he decided to obfuscate (intentionally make less readable) his code before upcoming contest. To obfuscate the code, Kostya first looks at the first variable name used in his program and rep...
In the only line of input there is a string *S* of lowercase English letters (1<=≤<=|*S*|<=≤<=500) — the identifiers of a program with removed whitespace characters.
If this program can be a result of Kostya's obfuscation, print "YES" (without quotes), otherwise print "NO".
[ "abacaba\n", "jinotega\n" ]
[ "YES\n", "NO\n" ]
In the first sample case, one possible list of identifiers would be "number string number character number string number". Here how Kostya would obfuscate the program: - replace all occurences of number with a, the result would be "a string a character a string a",- replace all occurences of string with b, the result...
[ { "input": "abacaba", "output": "YES" }, { "input": "jinotega", "output": "NO" }, { "input": "aaaaaaaaaaa", "output": "YES" }, { "input": "aba", "output": "YES" }, { "input": "bab", "output": "NO" }, { "input": "a", "output": "YES" }, { "in...
156
2,355,200
3
3,802
522
Closest Equals
[ "*special", "data structures" ]
null
null
You are given sequence *a*1,<=*a*2,<=...,<=*a**n* and *m* queries *l**j*,<=*r**j* (1<=≤<=*l**j*<=≤<=*r**j*<=≤<=*n*). For each query you need to print the minimum distance between such pair of elements *a**x* and *a**y* (*x*<=≠<=*y*), that: - both indexes of the elements lie within range [*l**j*,<=*r**j*], that is, *l...
The first line of the input contains a pair of integers *n*, *m* (1<=≤<=*n*,<=*m*<=≤<=5·105) — the length of the sequence and the number of queries, correspondingly. The second line contains the sequence of integers *a*1,<=*a*2,<=...,<=*a**n* (<=-<=109<=≤<=*a**i*<=≤<=109). Next *m* lines contain the queries, one pe...
Print *m* integers — the answers to each query. If there is no valid match for some query, please print -1 as an answer to this query.
[ "5 3\n1 1 2 3 2\n1 5\n2 4\n3 5\n", "6 5\n1 2 1 3 2 3\n4 6\n1 3\n2 5\n2 4\n1 6\n" ]
[ "1\n-1\n2\n", "2\n2\n3\n-1\n2\n" ]
none
[ { "input": "5 3\n1 1 2 3 2\n1 5\n2 4\n3 5", "output": "1\n-1\n2" }, { "input": "6 5\n1 2 1 3 2 3\n4 6\n1 3\n2 5\n2 4\n1 6", "output": "2\n2\n3\n-1\n2" }, { "input": "10 6\n2 2 1 5 6 4 9 8 5 4\n1 2\n1 10\n2 10\n2 9\n5 5\n2 8", "output": "1\n1\n4\n5\n-1\n-1" }, { "input": "1 1\...
108
20,172,800
0
3,808
920
Connected Components?
[ "data structures", "dfs and similar", "dsu", "graphs" ]
null
null
You are given an undirected graph consisting of *n* vertices and edges. Instead of giving you the edges that exist in the graph, we give you *m* unordered pairs (*x*,<=*y*) such that there is no edge between *x* and *y*, and if some pair of vertices is not listed in the input, then there is an edge between these verti...
The first line contains two integers *n* and *m* (1<=≤<=*n*<=≤<=200000, ). Then *m* lines follow, each containing a pair of integers *x* and *y* (1<=≤<=*x*,<=*y*<=≤<=*n*, *x*<=≠<=*y*) denoting that there is no edge between *x* and *y*. Each pair is listed at most once; (*x*,<=*y*) and (*y*,<=*x*) are considered the sa...
Firstly print *k* — the number of connected components in this graph. Then print *k* integers — the sizes of components. You should output these integers in non-descending order.
[ "5 5\n1 2\n3 4\n3 2\n4 2\n2 5\n" ]
[ "2\n1 4 " ]
none
[ { "input": "5 5\n1 2\n3 4\n3 2\n4 2\n2 5", "output": "2\n1 4 " }, { "input": "8 15\n2 1\n4 5\n2 4\n3 4\n2 5\n3 5\n2 6\n3 6\n5 6\n4 6\n2 7\n3 8\n2 8\n3 7\n6 7", "output": "1\n8 " }, { "input": "12 58\n1 2\n1 3\n1 4\n1 5\n1 6\n1 7\n1 8\n1 10\n1 11\n1 12\n2 3\n2 4\n2 5\n2 6\n2 7\n2 8\n2 9\n...
2,292
268,390,400
0
3,809
0
none
[ "none" ]
null
null
A factory produces thimbles in bulk. Typically, it can produce up to *a* thimbles a day. However, some of the machinery is defective, so it can currently only produce *b* thimbles each day. The factory intends to choose a *k*-day period to do maintenance and construction; it cannot produce any thimbles during this time...
The first line contains five integers *n*, *k*, *a*, *b*, and *q* (1<=≤<=*k*<=≤<=*n*<=≤<=200<=000, 1<=≤<=*b*<=&lt;<=*a*<=≤<=10 000, 1<=≤<=*q*<=≤<=200<=000) — the number of days, the length of the repair time, the production rates of the factory, and the number of updates, respectively. The next *q* lines contain the d...
For each query of the second type, print a line containing a single integer — the maximum number of orders that the factory can fill over all *n* days.
[ "5 2 2 1 8\n1 1 2\n1 5 3\n1 2 1\n2 2\n1 4 2\n1 3 2\n2 1\n2 3\n", "5 4 10 1 6\n1 1 5\n1 5 5\n1 3 2\n1 5 2\n2 1\n2 2\n" ]
[ "3\n6\n4\n", "7\n1\n" ]
Consider the first sample. We produce up to 1 thimble a day currently and will produce up to 2 thimbles a day after repairs. Repairs take 2 days. For the first question, we are able to fill 1 order on day 1, no orders on days 2 and 3 since we are repairing, no orders on day 4 since no thimbles have been ordered for t...
[ { "input": "5 2 2 1 8\n1 1 2\n1 5 3\n1 2 1\n2 2\n1 4 2\n1 3 2\n2 1\n2 3", "output": "3\n6\n4" }, { "input": "5 4 10 1 6\n1 1 5\n1 5 5\n1 3 2\n1 5 2\n2 1\n2 2", "output": "7\n1" }, { "input": "1 1 2 1 1\n2 1", "output": "0" } ]
93
0
0
3,815
769
k-Interesting Pairs Of Integers
[ "*special", "bitmasks", "brute force", "meet-in-the-middle" ]
null
null
Vasya has the sequence consisting of *n* integers. Vasya consider the pair of integers *x* and *y* k-interesting, if their binary representation differs from each other exactly in *k* bits. For example, if *k*<==<=2, the pair of integers *x*<==<=5 and *y*<==<=3 is k-interesting, because their binary representation *x*=...
The first line contains two integers *n* and *k* (2<=≤<=*n*<=≤<=105, 0<=≤<=*k*<=≤<=14) — the number of integers in Vasya's sequence and the number of bits in which integers in k-interesting pair should differ. The second line contains the sequence *a*1,<=*a*2,<=...,<=*a**n* (0<=≤<=*a**i*<=≤<=104), which Vasya has.
Print the number of pairs (*i*, *j*) so that *i*<=&lt;<=*j* and the pair of integers *a**i* and *a**j* is k-interesting.
[ "4 1\n0 3 2 1\n", "6 0\n200 100 100 100 200 200\n" ]
[ "4\n", "6\n" ]
In the first test there are 4 k-interesting pairs: - (1, 3), - (1, 4), - (2, 3), - (2, 4). In the second test *k* = 0. Consequently, integers in any k-interesting pair should be equal to themselves. Thus, for the second test there are 6 k-interesting pairs: - (1, 5), - (1, 6), - (2, 3), - (2, 4), - (3, 4), ...
[ { "input": "4 1\n0 3 2 1", "output": "4" }, { "input": "6 0\n200 100 100 100 200 200", "output": "6" }, { "input": "2 0\n1 1", "output": "1" }, { "input": "2 0\n0 0", "output": "1" }, { "input": "2 0\n10000 10000", "output": "1" }, { "input": "2 0\n0 1...
62
4,915,200
0
3,817
19
Points
[ "data structures" ]
D. Points
2
256
Pete and Bob invented a new interesting game. Bob takes a sheet of paper and locates a Cartesian coordinate system on it as follows: point (0,<=0) is located in the bottom-left corner, *Ox* axis is directed right, *Oy* axis is directed up. Pete gives Bob requests of three types: - add x y — on the sheet of paper Bob...
The first input line contains number *n* (1<=≤<=*n*<=≤<=2·105) — amount of requests. Then there follow *n* lines — descriptions of the requests. add x y describes the request to add a point, remove x y — the request to erase a point, find x y — the request to find the bottom-left point. All the coordinates in the input...
For each request of type find x y output in a separate line the answer to it — coordinates of the bottommost among the leftmost marked points, lying strictly above and to the right of point (*x*,<=*y*). If there are no points strictly above and to the right of point (*x*,<=*y*), output -1.
[ "7\nadd 1 1\nadd 3 4\nfind 0 0\nremove 1 1\nfind 0 0\nadd 1 1\nfind 0 0\n", "13\nadd 5 5\nadd 5 6\nadd 5 7\nadd 6 5\nadd 6 6\nadd 6 7\nadd 7 5\nadd 7 6\nadd 7 7\nfind 6 6\nremove 7 7\nfind 6 6\nfind 4 4\n" ]
[ "1 1\n3 4\n1 1\n", "7 7\n-1\n5 5\n" ]
none
[]
2,000
819,200
0
3,822
899
Months and Years
[ "implementation" ]
null
null
Everybody in Russia uses Gregorian calendar. In this calendar there are 31 days in January, 28 or 29 days in February (depending on whether the year is leap or not), 31 days in March, 30 days in April, 31 days in May, 30 in June, 31 in July, 31 in August, 30 in September, 31 in October, 30 in November, 31 in December. ...
The first line contains single integer *n* (1<=≤<=*n*<=≤<=24) — the number of integers. The second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (28<=≤<=*a**i*<=≤<=31) — the numbers you are to check.
If there are several consecutive months that fit the sequence, print "YES" (without quotes). Otherwise, print "NO" (without quotes). You can print each letter in arbitrary case (small or large).
[ "4\n31 31 30 31\n", "2\n30 30\n", "5\n29 31 30 31 30\n", "3\n31 28 30\n", "3\n31 31 28\n" ]
[ "Yes\n\n", "No\n\n", "Yes\n\n", "No\n\n", "Yes\n\n" ]
In the first example the integers can denote months July, August, September and October. In the second example the answer is no, because there are no two consecutive months each having 30 days. In the third example the months are: February (leap year) — March — April – May — June. In the fourth example the number of...
[ { "input": "4\n31 31 30 31", "output": "Yes" }, { "input": "2\n30 30", "output": "No" }, { "input": "5\n29 31 30 31 30", "output": "Yes" }, { "input": "3\n31 28 30", "output": "No" }, { "input": "3\n31 31 28", "output": "Yes" }, { "input": "24\n29 28 3...
31
0
0
3,829
653
Bear and Compressing
[ "brute force", "dfs and similar", "dp", "strings" ]
null
null
Limak is a little polar bear. Polar bears hate long strings and thus they like to compress them. You should also know that Limak is so young that he knows only first six letters of the English alphabet: 'a', 'b', 'c', 'd', 'e' and 'f'. You are given a set of *q* possible operations. Limak can perform them in any order...
The first line contains two integers *n* and *q* (2<=≤<=*n*<=≤<=6, 1<=≤<=*q*<=≤<=36) — the length of the initial string and the number of available operations. The next *q* lines describe the possible operations. The *i*-th of them contains two strings *a**i* and *b**i* (|*a**i*|<==<=2,<=|*b**i*|<==<=1). It's guarante...
Print the number of strings of length *n* that Limak will be able to transform to string "a" by applying only operations given in the input.
[ "3 5\nab a\ncc c\nca a\nee c\nff d\n", "2 8\naf e\ndc d\ncc f\nbc b\nda b\neb a\nbb b\nff c\n", "6 2\nbb a\nba a\n" ]
[ "4\n", "1\n", "0\n" ]
In the first sample, we count initial strings of length 3 from which Limak can get a required string "a". There are 4 such strings: "abb", "cab", "cca", "eea". The first one Limak can compress using operation 1 two times (changing "ab" to a single "a"). The first operation would change "abb" to "ab" and the second oper...
[ { "input": "3 5\nab a\ncc c\nca a\nee c\nff d", "output": "4" }, { "input": "2 8\naf e\ndc d\ncc f\nbc b\nda b\neb a\nbb b\nff c", "output": "1" }, { "input": "6 2\nbb a\nba a", "output": "0" }, { "input": "2 5\nfe b\nbb a\naf b\nfd b\nbf c", "output": "1" }, { "i...
108
5,324,800
3
3,833
963
Alternating Sum
[ "math", "number theory" ]
null
null
You are given two integers $a$ and $b$. Moreover, you are given a sequence $s_0, s_1, \dots, s_{n}$. All values in $s$ are integers $1$ or $-1$. It's known that sequence is $k$-periodic and $k$ divides $n+1$. In other words, for each $k \leq i \leq n$ it's satisfied that $s_{i} = s_{i - k}$. Find out the non-negative ...
The first line contains four integers $n, a, b$ and $k$ $(1 \leq n \leq 10^{9}, 1 \leq a, b \leq 10^{9}, 1 \leq k \leq 10^{5})$. The second line contains a sequence of length $k$ consisting of characters '+' and '-'. If the $i$-th character (0-indexed) is '+', then $s_{i} = 1$, otherwise $s_{i} = -1$. Note that onl...
Output a single integer — value of given expression modulo $10^{9} + 9$.
[ "2 2 3 3\n+-+\n", "4 1 5 1\n-\n" ]
[ "7\n", "999999228\n" ]
In the first example: $(\sum \limits_{i=0}^{n} s_{i} a^{n - i} b^{i})$ = $2^{2} 3^{0} - 2^{1} 3^{1} + 2^{0} 3^{2}$ = 7 In the second example: $(\sum \limits_{i=0}^{n} s_{i} a^{n - i} b^{i}) = -1^{4} 5^{0} - 1^{3} 5^{1} - 1^{2} 5^{2} - 1^{1} 5^{3} - 1^{0} 5^{4} = -781 \equiv 999999228 \pmod{10^{9} + 9}$.
[ { "input": "2 2 3 3\n+-+", "output": "7" }, { "input": "4 1 5 1\n-", "output": "999999228" }, { "input": "1 1 4 2\n-+", "output": "3" }, { "input": "3 1 4 4\n+--+", "output": "45" }, { "input": "5 1 1 6\n++---+", "output": "0" }, { "input": "5 2 2 6\n+...
0
0
-1
3,837
550
Two Substrings
[ "brute force", "dp", "greedy", "implementation", "strings" ]
null
null
You are given string *s*. Your task is to determine if the given string *s* contains two non-overlapping substrings "AB" and "BA" (the substrings can go in any order).
The only line of input contains a string *s* of length between 1 and 105 consisting of uppercase Latin letters.
Print "YES" (without the quotes), if string *s* contains two non-overlapping substrings "AB" and "BA", and "NO" otherwise.
[ "ABA\n", "BACFAB\n", "AXBYBXA\n" ]
[ "NO\n", "YES\n", "NO\n" ]
In the first sample test, despite the fact that there are substrings "AB" and "BA", their occurrences overlap, so the answer is "NO". In the second sample test there are the following occurrences of the substrings: BACFAB. In the third sample test there is no substring "AB" nor substring "BA".
[ { "input": "ABA", "output": "NO" }, { "input": "BACFAB", "output": "YES" }, { "input": "AXBYBXA", "output": "NO" }, { "input": "ABABAB", "output": "YES" }, { "input": "BBBBBBBBBB", "output": "NO" }, { "input": "ABBA", "output": "YES" }, { "...
46
0
0
3,840
333
Secrets
[ "greedy" ]
null
null
Gerald has been selling state secrets at leisure. All the secrets cost the same: *n* marks. The state which secrets Gerald is selling, has no paper money, only coins. But there are coins of all positive integer denominations that are powers of three: 1 mark, 3 marks, 9 marks, 27 marks and so on. There are no coins of o...
The single line contains a single integer *n* (1<=≤<=*n*<=≤<=1017). Please, do not use the %lld specifier to read or write 64 bit integers in С++. It is preferred to use the cin, cout streams or the %I64d specifier.
In a single line print an integer: the maximum number of coins the unlucky buyer could have paid with.
[ "1\n", "4\n" ]
[ "1\n", "2\n" ]
In the first test case, if a buyer has exactly one coin of at least 3 marks, then, to give Gerald one mark, he will have to give this coin. In this sample, the customer can not have a coin of one mark, as in this case, he will be able to give the money to Gerald without any change. In the second test case, if the buye...
[ { "input": "1", "output": "1" }, { "input": "4", "output": "2" }, { "input": "3", "output": "1" }, { "input": "8", "output": "3" }, { "input": "10", "output": "4" }, { "input": "100000000000000000", "output": "33333333333333334" }, { "input...
184
0
3
3,842
22
System Administrator
[ "graphs" ]
C. System Administrator
1
256
Bob got a job as a system administrator in X corporation. His first task was to connect *n* servers with the help of *m* two-way direct connection so that it becomes possible to transmit data from one server to any other server via these connections. Each direct connection has to link two different servers, each pair o...
The first input line contains 3 space-separated integer numbers *n*, *m*, *v* (3<=≤<=*n*<=≤<=105,<=0<=≤<=*m*<=≤<=105,<=1<=≤<=*v*<=≤<=*n*), *n* — amount of servers, *m* — amount of direct connections, *v* — index of the server that fails and leads to the failure of the whole system.
If it is impossible to connect the servers in the required way, output -1. Otherwise output *m* lines with 2 numbers each — description of all the direct connections in the system. Each direct connection is described by two numbers — indexes of two servers, linked by this direct connection. The servers are numbered fro...
[ "5 6 3\n", "6 100 1\n" ]
[ "1 2\n2 3\n3 4\n4 5\n1 3\n3 5\n", "-1\n" ]
none
[ { "input": "5 6 3", "output": "1 3\n2 3\n4 3\n5 3\n1 2\n1 4" }, { "input": "6 100 1", "output": "-1" }, { "input": "10 26 1", "output": "2 1\n3 1\n4 1\n5 1\n6 1\n7 1\n8 1\n9 1\n10 1\n2 3\n2 4\n2 5\n2 6\n2 7\n2 8\n2 9\n3 4\n3 5\n3 6\n3 7\n3 8\n3 9\n4 5\n4 6\n4 7\n4 8" }, { "in...
109
0
0
3,843
180
Defragmentation
[ "implementation" ]
null
null
In this problem you have to implement an algorithm to defragment your hard disk. The hard disk consists of a sequence of clusters, numbered by integers from 1 to *n*. The disk has *m* recorded files, the *i*-th file occupies clusters with numbers *a**i*,<=1, *a**i*,<=2, ..., *a**i*,<=*n**i*. These clusters are not nece...
The first line contains two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=200) — the number of clusters and the number of files, correspondingly. Next *m* lines contain descriptions of the files. The first number in the line is *n**i* (*n**i*<=≥<=1), the number of clusters occupied by the *i*-th file. Then follow *n**i* nu...
In the first line print a single integer *k* (0<=≤<=*k*<=≤<=2*n*) — the number of operations needed to defragment the disk. Next *k* lines should contain the operations' descriptions as "*i* *j*" (copy the contents of the cluster number *i* to the cluster number *j*).
[ "7 2\n2 1 2\n3 3 4 5\n", "7 2\n2 1 3\n3 2 4 5\n" ]
[ "0\n", "3\n2 6\n3 2\n6 3\n" ]
Let's say that a disk consists of 8 clusters and contains two files. The first file occupies two clusters and the second file occupies three clusters. Let's look at examples of correct and incorrect positions of files after defragmentation. Example 2: each file must occupy a contiguous area of memory. Example 3: the...
[ { "input": "7 2\n2 1 2\n3 3 4 5", "output": "0" }, { "input": "7 2\n2 1 3\n3 2 4 5", "output": "3\n2 6\n3 2\n6 3" }, { "input": "2 1\n1 2", "output": "1\n2 1" }, { "input": "3 1\n2 3 1", "output": "2\n1 2\n3 1" }, { "input": "3 2\n1 3\n1 2", "output": "1\n3 1"...
248
512,000
3
3,845
952
2 + 2 != 4
[]
null
null
One very experienced problem writer decided to prepare a problem for April Fools Day contest. The task was very simple - given an arithmetic expression, return the result of evaluating this expression. However, looks like there is a bug in the reference solution...
The only line of input data contains the arithmetic expression. The expression will contain between 2 and 10 operands, separated with arithmetic signs plus and/or minus. Each operand will be an integer between 0 and 255, inclusive.
Reproduce the output of the reference solution, including the bug.
[ "8-7+6-5+4-3+2-1-0\n", "2+2\n", "112-37\n" ]
[ "4\n", "-46\n", "375\n" ]
none
[ { "input": "8-7+6-5+4-3+2-1-0", "output": "4" }, { "input": "2+2", "output": "-46" }, { "input": "112-37", "output": "375" }, { "input": "255+255+255+255+255+255+255+255+255+255", "output": "-42450" }, { "input": "0-255-255-255-255-255-255-255-255-255", "outpu...
0
0
-1
3,846
25
Roads in Berland
[ "graphs", "shortest paths" ]
C. Roads in Berland
2
256
There are *n* cities numbered from 1 to *n* in Berland. Some of them are connected by two-way roads. Each road has its own length — an integer number from 1 to 1000. It is known that from each city it is possible to get to any other city by existing roads. Also for each pair of cities it is known the shortest distance ...
The first line contains integer *n* (2<=≤<=*n*<=≤<=300) — amount of cities in Berland. Then there follow *n* lines with *n* integer numbers each — the matrix of shortest distances. *j*-th integer in the *i*-th row — *d**i*,<=*j*, the shortest distance between cities *i* and *j*. It is guaranteed that *d**i*,<=*i*<==<=0...
Output *k* space-separated integers *q**i* (1<=≤<=*i*<=≤<=*k*). *q**i* should be equal to the sum of shortest distances between all pairs of cities after the construction of roads with indexes from 1 to *i*. Roads are numbered from 1 in the input order. Each pair of cities should be taken into account in the sum exactl...
[ "2\n0 5\n5 0\n1\n1 2 3\n", "3\n0 4 5\n4 0 9\n5 9 0\n2\n2 3 8\n1 2 1\n" ]
[ "3 ", "17 12 " ]
none
[ { "input": "2\n0 5\n5 0\n1\n1 2 3", "output": "3 " }, { "input": "3\n0 4 5\n4 0 9\n5 9 0\n2\n2 3 8\n1 2 1", "output": "17 12 " }, { "input": "3\n0 983 173\n983 0 810\n173 810 0\n3\n3 2 567\n2 3 767\n1 2 763", "output": "1480 1480 1480 " }, { "input": "4\n0 537 1064 656\n537 0...
2,000
12,185,600
0
3,847
715
Create a Maze
[ "constructive algorithms" ]
null
null
ZS the Coder loves mazes. Your job is to create one so that he can play with it. A maze consists of *n*<=×<=*m* rooms, and the rooms are arranged in *n* rows (numbered from the top to the bottom starting from 1) and *m* columns (numbered from the left to the right starting from 1). The room in the *i*-th row and *j*-th...
The first and only line of the input contains a single integer *T* (1<=≤<=*T*<=≤<=1018), the difficulty of the required maze.
The first line should contain two integers *n* and *m* (1<=≤<=*n*,<=*m*<=≤<=50) — the number of rows and columns of the maze respectively. The next line should contain a single integer *k* (0<=≤<=*k*<=≤<=300) — the number of locked doors in the maze. Then, *k* lines describing locked doors should follow. Each of them...
[ "3\n", "4\n" ]
[ "3 2\n0\n", "4 3\n3\n1 2 2 2\n3 2 3 3\n1 3 2 3" ]
Here are how the sample input and output looks like. The colored arrows denotes all the possible paths while a red cross denotes a locked door. In the first sample case: In the second sample case:
[ { "input": "3", "output": "4 4\n5\n1 2 2 2\n1 3 2 3\n1 4 2 4\n2 1 2 2\n4 1 4 2" }, { "input": "4", "output": "4 4\n4\n1 2 2 2\n1 3 2 3\n2 1 2 2\n4 1 4 2" }, { "input": "576460752303423488", "output": "48 48\n233\n1 2 2 2\n1 3 2 3\n2 1 2 2\n2 4 2 5\n2 6 3 6\n2 7 3 7\n3 4 3 5\n3 5 4 5\...
93
2,457,600
3
3,848
294
Shaass and Bookshelf
[ "dp", "greedy" ]
null
null
Shaass has *n* books. He wants to make a bookshelf for all his books. He wants the bookshelf's dimensions to be as small as possible. The thickness of the *i*-th book is *t**i* and its pages' width is equal to *w**i*. The thickness of each book is either 1 or 2. All books have the same page heights. Shaass puts the bo...
The first line of the input contains an integer *n*, (1<=≤<=*n*<=≤<=100). Each of the next *n* lines contains two integers *t**i* and *w**i* denoting the thickness and width of the *i*-th book correspondingly, (1<=≤<=*t**i*<=≤<=2,<=1<=≤<=*w**i*<=≤<=100).
On the only line of the output print the minimum total thickness of the vertical books that we can achieve.
[ "5\n1 12\n1 3\n2 15\n2 5\n2 1\n", "3\n1 10\n2 1\n2 4\n" ]
[ "5\n", "3\n" ]
none
[ { "input": "5\n1 12\n1 3\n2 15\n2 5\n2 1", "output": "5" }, { "input": "3\n1 10\n2 1\n2 4", "output": "3" }, { "input": "10\n2 10\n2 4\n2 8\n2 3\n2 5\n2 6\n1 2\n1 10\n1 10\n2 5", "output": "12" }, { "input": "1\n2 7", "output": "2" }, { "input": "50\n1 24\n1 16\n1...
93
10,956,800
0
3,858
896
Nephren gives a riddle
[ "binary search", "dfs and similar" ]
null
null
Nephren is playing a game with little leprechauns. She gives them an infinite array of strings, *f*0... ∞. *f*0 is "What are you doing at the end of the world? Are you busy? Will you save us?". She wants to let more people know about it, so she defines *f**i*<==<= "What are you doing while sending "*f**i*<=-<=1"? ...
The first line contains one integer *q* (1<=≤<=*q*<=≤<=10) — the number of Nephren's questions. Each of the next *q* lines describes Nephren's question and contains two integers *n* and *k* (0<=≤<=*n*<=≤<=105,<=1<=≤<=*k*<=≤<=1018).
One line containing *q* characters. The *i*-th character in it should be the answer for the *i*-th query.
[ "3\n1 1\n1 2\n1 111111111111\n", "5\n0 69\n1 194\n1 139\n0 47\n1 66\n", "10\n4 1825\n3 75\n3 530\n4 1829\n4 1651\n3 187\n4 584\n4 255\n4 774\n2 474\n" ]
[ "Wh.", "abdef", "Areyoubusy" ]
For the first two examples, refer to *f*<sub class="lower-index">0</sub> and *f*<sub class="lower-index">1</sub> given in the legend.
[ { "input": "3\n1 1\n1 2\n1 111111111111", "output": "Wh." }, { "input": "5\n0 69\n1 194\n1 139\n0 47\n1 66", "output": "abdef" }, { "input": "10\n4 1825\n3 75\n3 530\n4 1829\n4 1651\n3 187\n4 584\n4 255\n4 774\n2 474", "output": "Areyoubusy" }, { "input": "1\n0 1", "outpu...
31
102,400
-1
3,859
626
Simple Skewness
[ "binary search", "math", "ternary search" ]
null
null
Define the simple skewness of a collection of numbers to be the collection's mean minus its median. You are given a list of *n* (not necessarily distinct) integers. Find the non-empty subset (with repetition) with the maximum simple skewness. The mean of a collection is the average of its elements. The median of a col...
The first line of the input contains a single integer *n* (1<=≤<=*n*<=≤<=200 000) — the number of elements in the list. The second line contains *n* integers *x**i* (0<=≤<=*x**i*<=≤<=1<=000<=000) — the *i*th element of the list.
In the first line, print a single integer *k* — the size of the subset. In the second line, print *k* integers — the elements of the subset in any order. If there are multiple optimal subsets, print any.
[ "4\n1 2 3 12\n", "4\n1 1 2 2\n", "2\n1 2\n" ]
[ "3\n1 2 12 \n", "3\n1 1 2 \n", "2\n1 2\n" ]
In the first case, the optimal subset is <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/04cdbd07a0375de9c557422eca077386392a9349.png" style="max-width: 100.0%;max-height: 100.0%;"/>, which has mean 5, median 2, and simple skewness of 5 - 2 = 3. In the second case, the optimal subset is <i...
[ { "input": "4\n1 2 3 12", "output": "3\n1 2 12 " }, { "input": "4\n1 1 2 2", "output": "3\n1 1 2 " }, { "input": "2\n1 2", "output": "2\n1 2" }, { "input": "1\n1000000", "output": "1\n1000000 " }, { "input": "20\n999999 999998 999996 999992 999984 999968 999936 99...
30
0
-1
3,874
10
LCIS
[ "dp" ]
D. LCIS
1
256
This problem differs from one which was on the online contest. The sequence *a*1,<=*a*2,<=...,<=*a**n* is called increasing, if *a**i*<=&lt;<=*a**i*<=+<=1 for *i*<=&lt;<=*n*. The sequence *s*1,<=*s*2,<=...,<=*s**k* is called the subsequence of the sequence *a*1,<=*a*2,<=...,<=*a**n*, if there exist such a set of inde...
The first line contains an integer *n* (1<=≤<=*n*<=≤<=500) — the length of the first sequence. The second line contains *n* space-separated integers from the range [0,<=109] — elements of the first sequence. The third line contains an integer *m* (1<=≤<=*m*<=≤<=500) — the length of the second sequence. The fourth line ...
In the first line output *k* — the length of the longest common increasing subsequence. In the second line output the subsequence itself. Separate the elements with a space. If there are several solutions, output any.
[ "7\n2 3 1 6 5 4 6\n4\n1 3 5 6\n", "5\n1 2 0 2 1\n3\n1 0 1\n" ]
[ "3\n3 5 6 \n", "2\n0 1 \n" ]
none
[ { "input": "7\n2 3 1 6 5 4 6\n4\n1 3 5 6", "output": "3\n3 5 6 " }, { "input": "5\n1 2 0 2 1\n3\n1 0 1", "output": "2\n0 1 " }, { "input": "2\n6 10\n3\n6 3 3", "output": "1\n6 " }, { "input": "1\n7\n2\n7 9", "output": "1\n7 " }, { "input": "3\n37 49 24\n3\n33 5 70...
77
204,800
0
3,880
569
Music
[ "implementation", "math" ]
null
null
Little Lesha loves listening to music via his smartphone. But the smartphone doesn't have much memory, so Lesha listens to his favorite songs in a well-known social network InTalk. Unfortunately, internet is not that fast in the city of Ekaterinozavodsk and the song takes a lot of time to download. But Lesha is quite ...
The single line contains three integers *T*,<=*S*,<=*q* (2<=≤<=*q*<=≤<=104, 1<=≤<=*S*<=&lt;<=*T*<=≤<=105).
Print a single integer — the number of times the song will be restarted.
[ "5 2 2\n", "5 4 7\n", "6 2 3\n" ]
[ "2\n", "1\n", "1\n" ]
In the first test, the song is played twice faster than it is downloaded, which means that during four first seconds Lesha reaches the moment that has not been downloaded, and starts the song again. After another two seconds, the song is downloaded completely, and thus, Lesha starts the song twice. In the second test,...
[ { "input": "5 2 2", "output": "2" }, { "input": "5 4 7", "output": "1" }, { "input": "6 2 3", "output": "1" }, { "input": "2 1 2", "output": "1" }, { "input": "2 1 3", "output": "1" }, { "input": "2 1 10000", "output": "1" }, { "input": "12...
46
0
0
3,885
39
Company Income Growth
[ "greedy" ]
B. Company Income Growth
2
64
Petya works as a PR manager for a successful Berland company BerSoft. He needs to prepare a presentation on the company income growth since 2001 (the year of its founding) till now. Petya knows that in 2001 the company income amounted to *a*1 billion bourles, in 2002 — to *a*2 billion, ..., and in the current (2000<=+<...
The first line contains an integer *n* (1<=≤<=*n*<=≤<=100). The next line contains *n* integers *a**i* (<=-<=100<=≤<=*a**i*<=≤<=100). The number *a**i* determines the income of BerSoft company in the (2000<=+<=*i*)-th year. The numbers in the line are separated by spaces.
Output *k* — the maximum possible length of a perfect sequence. In the next line output the sequence of years *y*1, *y*2, ..., *y**k*. Separate the numbers by spaces. If the answer is not unique, output any. If no solution exist, output one number 0.
[ "10\n-2 1 1 3 2 3 4 -10 -2 5\n", "3\n-1 -2 -3\n" ]
[ "5\n2002 2005 2006 2007 2010\n", "0\n" ]
none
[ { "input": "10\n-2 1 1 3 2 3 4 -10 -2 5", "output": "5\n2002 2005 2006 2007 2010 " }, { "input": "3\n-1 -2 -3", "output": "0" }, { "input": "1\n0", "output": "0" }, { "input": "1\n0", "output": "0" }, { "input": "2\n-1 1", "output": "1\n2002 " }, { "in...
156
7,065,600
3.908357
3,889
337
Book of Evil
[ "dfs and similar", "divide and conquer", "dp", "trees" ]
null
null
Paladin Manao caught the trail of the ancient Book of Evil in a swampy area. This area contains *n* settlements numbered from 1 to *n*. Moving through the swamp is very difficult, so people tramped exactly *n*<=-<=1 paths. Each of these paths connects some pair of settlements and is bidirectional. Moreover, it is possi...
The first line contains three space-separated integers *n*, *m* and *d* (1<=≤<=*m*<=≤<=*n*<=≤<=100000; 0<=≤<=*d*<=≤<=*n*<=-<=1). The second line contains *m* distinct space-separated integers *p*1,<=*p*2,<=...,<=*p**m* (1<=≤<=*p**i*<=≤<=*n*). Then *n*<=-<=1 lines follow, each line describes a path made in the area. A p...
Print a single number — the number of settlements that may contain the Book of Evil. It is possible that Manao received some controversial information and there is no settlement that may contain the Book. In such case, print 0.
[ "6 2 3\n1 2\n1 5\n2 3\n3 4\n4 5\n5 6\n" ]
[ "3\n" ]
Sample 1. The damage range of the Book of Evil equals 3 and its effects have been noticed in settlements 1 and 2. Thus, it can be in settlements 3, 4 or 5.
[ { "input": "6 2 3\n1 2\n1 5\n2 3\n3 4\n4 5\n5 6", "output": "3" }, { "input": "2 2 1\n2 1\n1 2", "output": "2" }, { "input": "50 2 5\n9 14\n46 34\n40 35\n44 30\n32 16\n1 38\n48 2\n17 14\n50 25\n6 1\n45 19\n21 15\n22 11\n15 33\n8 28\n2 32\n10 22\n37 3\n43 39\n25 16\n9 19\n16 3\n28 32\n20 ...
122
268,390,400
0
3,891
592
The Big Race
[ "math" ]
null
null
Vector Willman and Array Bolt are the two most famous athletes of Byteforces. They are going to compete in a race with a distance of *L* meters today. Willman and Bolt have exactly the same speed, so when they compete the result is always a tie. That is a problem for the organizers because they want a winner. While ...
The first line of the input contains three integers *t*, *w* and *b* (1<=≤<=*t*,<=*w*,<=*b*<=≤<=5·1018) — the maximum possible length of the racetrack, the length of Willman's steps and the length of Bolt's steps respectively.
Print the answer to the problem as an irreducible fraction . Follow the format of the samples output. The fraction (*p* and *q* are integers, and both *p*<=≥<=0 and *q*<=&gt;<=0 holds) is called irreducible, if there is no such integer *d*<=&gt;<=1, that both *p* and *q* are divisible by *d*.
[ "10 3 2\n", "7 1 2\n" ]
[ "3/10\n", "3/7\n" ]
In the first sample Willman and Bolt will tie in case 1, 6 or 7 are chosen as the length of the racetrack.
[ { "input": "10 3 2", "output": "3/10" }, { "input": "7 1 2", "output": "3/7" }, { "input": "1 1 1", "output": "1/1" }, { "input": "5814 31 7", "output": "94/2907" }, { "input": "94268 813 766", "output": "765/94268" }, { "input": "262610 5583 4717", ...
46
0
0
3,899
931
World Cup
[ "constructive algorithms", "implementation" ]
null
null
The last stage of Football World Cup is played using the play-off system. There are *n* teams left in this stage, they are enumerated from 1 to *n*. Several rounds are held, in each round the remaining teams are sorted in the order of their ids, then the first in this order plays with the second, the third — with the ...
The only line contains three integers *n*, *a* and *b* (2<=≤<=*n*<=≤<=256, 1<=≤<=*a*,<=*b*<=≤<=*n*) — the total number of teams, and the ids of the teams that Arkady is interested in. It is guaranteed that *n* is such that in each round an even number of team advance, and that *a* and *b* are not equal.
In the only line print "Final!" (without quotes), if teams *a* and *b* can meet in the Final. Otherwise, print a single integer — the number of the round in which teams *a* and *b* can meet. The round are enumerated from 1.
[ "4 1 2\n", "8 2 6\n", "8 7 5\n" ]
[ "1\n", "Final!\n", "2\n" ]
In the first example teams 1 and 2 meet in the first round. In the second example teams 2 and 6 can only meet in the third round, which is the Final, if they win all their opponents in earlier rounds. In the third example the teams with ids 7 and 5 can meet in the second round, if they win their opponents in the firs...
[ { "input": "4 1 2", "output": "1" }, { "input": "8 2 6", "output": "Final!" }, { "input": "8 7 5", "output": "2" }, { "input": "128 30 98", "output": "Final!" }, { "input": "256 128 256", "output": "Final!" }, { "input": "256 2 127", "output": "7" ...
61
5,632,000
0
3,904
51
bHTML Tables Analisys
[ "expression parsing" ]
B. bHTML Tables Analisys
2
256
In this problem is used an extremely simplified version of HTML table markup. Please use the statement as a formal document and read it carefully. A string is a bHTML table, if it satisfies the grammar: Blanks in the grammar are only for purposes of illustration, in the given data there will be no spaces. The bHTML ...
For convenience, input data can be separated into non-empty lines in an arbitrary manner. The input data consist of no more than 10 lines. Combine (concatenate) all the input lines into one, to get a text representation *s* of the specified table. String *s* corresponds to the given grammar (the root element of grammar...
Print the sizes of all the tables in the non-decreasing order.
[ "&lt;table&gt;&lt;tr&gt;&lt;td&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;\n", "&lt;table&gt;\n&lt;tr&gt;\n&lt;td&gt;\n&lt;table&gt;&lt;tr&gt;&lt;td&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;/\ntd\n&gt;&lt;/tr&gt;&lt;tr\n&gt;&lt;td&gt;&lt;/td&gt;&lt;/tr&gt;&lt;tr&gt;&lt;td&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&g...
[ "1 ", "1 4 ", "1 1 1 3 " ]
none
[ { "input": "<table><tr><td></td></tr></table>", "output": "1 " }, { "input": "<table>\n<tr>\n<td>\n<table><tr><td></td></tr><tr><td></\ntd\n></tr><tr\n><td></td></tr><tr><td></td></tr></table>\n</td>\n</tr>\n</table>", "output": "1 4 " }, { "input": "<table><tr><td>\n<table><tr><td>\n<ta...
62
0
-1
3,907
845
Luba And The Ticket
[ "brute force", "greedy", "implementation" ]
null
null
Luba has a ticket consisting of 6 digits. In one move she can choose digit in any position and replace it with arbitrary digit. She wants to know the minimum number of digits she needs to replace in order to make the ticket lucky. The ticket is considered lucky if the sum of first three digits equals to the sum of las...
You are given a string consisting of 6 characters (all characters are digits from 0 to 9) — this string denotes Luba's ticket. The ticket can start with the digit 0.
Print one number — the minimum possible number of digits Luba needs to replace to make the ticket lucky.
[ "000000\n", "123456\n", "111000\n" ]
[ "0\n", "2\n", "1\n" ]
In the first example the ticket is already lucky, so the answer is 0. In the second example Luba can replace 4 and 5 with zeroes, and the ticket will become lucky. It's easy to see that at least two replacements are required. In the third example Luba can replace any zero with 3. It's easy to see that at least one re...
[ { "input": "000000", "output": "0" }, { "input": "123456", "output": "2" }, { "input": "111000", "output": "1" }, { "input": "120111", "output": "0" }, { "input": "999999", "output": "0" }, { "input": "199880", "output": "1" }, { "input": "...
93
307,200
0
3,915
111
Petya and Rectangle
[]
E. Petya and Rectangle
5
256
Little Petya loves playing with rectangles. Mom bought Petya a rectangle divided into cells *n*<=×<=*m* in size (containing *n* rows, *m* columns). Petya marked two different cells of the rectangle and now he is solving the following task: Let's define a simple path between those two cells as a sequence of distinct ce...
The first line contains space-separated integers *n* and *m* (4<=≤<=*n*,<=*m*<=≤<=1000) — the number of rows and the number of columns in the rectangle, correspondingly. The second line contains space-separated integers *x*1 and *y*1 — the coordinates of the first marked cell. The third line contains space-separated in...
In the first line print the length of the found path — *k*. In the next lines print *k* pairs of integers, one per line — coordinates of the cells that constitute the found path in the order, in which they follow in the path (the path must go from cell (*x*1,<=*y*1) to cell (*x*2,<=*y*2)). If there are several solution...
[ "4 4\n2 2\n3 3\n" ]
[ "15\n2 2\n1 2\n1 1\n2 1\n3 1\n4 1\n4 2\n4 3\n4 4\n3 4\n2 4\n1 4\n1 3\n2 3\n3 3\n" ]
The statement test is described in the picture:
[]
92
0
0
3,919
208
Police Station
[ "dp", "graphs", "shortest paths" ]
null
null
The Berland road network consists of *n* cities and of *m* bidirectional roads. The cities are numbered from 1 to *n*, where the main capital city has number *n*, and the culture capital — number 1. The road network is set up so that it is possible to reach any city from any other one by the roads. Moving on each road ...
The first input line contains two integers *n* and *m* (2<=≤<=*n*<=≤<=100, ) — the number of cities and the number of roads in Berland, correspondingly. Next *m* lines contain pairs of integers *v**i*, *u**i* (1<=≤<=*v**i*,<=*u**i*<=≤<=*n*, *v**i*<=≠<=*u**i*) — the numbers of cities that are connected by the *i*-th roa...
Print the maximum possible value of the average number of safe roads among all shortest paths from the culture capital to the main one. The answer will be considered valid if its absolute or relative inaccuracy does not exceed 10<=-<=6.
[ "4 4\n1 2\n2 4\n1 3\n3 4\n", "11 14\n1 2\n1 3\n2 4\n3 4\n4 5\n4 6\n5 11\n6 11\n1 8\n8 9\n9 7\n11 7\n1 10\n10 4\n" ]
[ "1.000000000000\n", "1.714285714286\n" ]
In the first sample you can put a police station in one of the capitals, then each path will have exactly one safe road. If we place the station not in the capital, then the average number of safe roads will also make <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/8f23cc2cd3bef67bde56e1691...
[]
60
0
0
3,942
1,004
Sonya and Exhibition
[ "constructive algorithms", "greedy", "implementation", "math" ]
null
null
Sonya decided to organize an exhibition of flowers. Since the girl likes only roses and lilies, she decided that only these two kinds of flowers should be in this exhibition. There are $n$ flowers in a row in the exhibition. Sonya can put either a rose or a lily in the $i$-th position. Thus each of $n$ positions shoul...
The first line contains two integers $n$ and $m$ ($1\leq n, m\leq 10^3$) — the number of flowers and visitors respectively. Each of the next $m$ lines contains two integers $l_i$ and $r_i$ ($1\leq l_i\leq r_i\leq n$), meaning that $i$-th visitor will visit all flowers from $l_i$ to $r_i$ inclusive.
Print the string of $n$ characters. The $i$-th symbol should be «0» if you want to put a rose in the $i$-th position, otherwise «1» if you want to put a lily. If there are multiple answers, print any.
[ "5 3\n1 3\n2 4\n2 5\n", "6 3\n5 6\n1 4\n4 6\n" ]
[ "01100", "110010" ]
In the first example, Sonya can put roses in the first, fourth, and fifth positions, and lilies in the second and third positions; - in the segment $[1\ldots3]$, there are one rose and two lilies, so the beauty is equal to $1\cdot 2=2$; - in the segment $[2\ldots4]$, there are one rose and two lilies, so the beauty ...
[ { "input": "5 3\n1 3\n2 4\n2 5", "output": "01010" }, { "input": "6 3\n5 6\n1 4\n4 6", "output": "010101" }, { "input": "10 4\n3 3\n1 6\n9 9\n10 10", "output": "0101010101" }, { "input": "1 1\n1 1", "output": "0" }, { "input": "1000 10\n3 998\n2 1000\n1 999\n2 100...
108
0
0
3,947
27
Unordered Subsequence
[ "constructive algorithms", "greedy" ]
C. Unordered Subsequence
2
256
The sequence is called ordered if it is non-decreasing or non-increasing. For example, sequnces [3, 1, 1, 0] and [1, 2, 3, 100] are ordered, but the sequence [1, 3, 3, 1] is not. You are given a sequence of numbers. You are to find it's shortest subsequence which is not ordered. A subsequence is a sequence that can be...
The first line of the input contains one integer *n* (1<=≤<=*n*<=≤<=105). The second line contains *n* space-separated integers — the given sequence. All numbers in this sequence do not exceed 106 by absolute value.
If the given sequence does not contain any unordered subsequences, output 0. Otherwise, output the length *k* of the shortest such subsequence. Then output *k* integers from the range [1..*n*] — indexes of the elements of this subsequence. If there are several solutions, output any of them.
[ "5\n67 499 600 42 23\n", "3\n1 2 3\n", "3\n2 3 1\n" ]
[ "3\n1 3 5\n", "0\n", "3\n1 2 3\n" ]
none
[ { "input": "3\n3 1 2", "output": "3\n1 2 3" }, { "input": "1\n-895376", "output": "0" }, { "input": "2\n166442 61629", "output": "0" }, { "input": "3\n-771740 -255752 -300809", "output": "3\n1 2 3" }, { "input": "4\n-227347 -573134 -671045 11011", "output": "3...
218
0
-1
3,949
877
Ann and Books
[ "data structures", "flows", "hashing" ]
null
null
In Ann's favorite book shop are as many as *n* books on math and economics. Books are numbered from 1 to *n*. Each of them contains non-negative number of problems. Today there is a sale: any subsegment of a segment from *l* to *r* can be bought at a fixed price. Ann decided that she wants to buy such non-empty subs...
The first line contains two integers *n* and *k* (1<=≤<=*n*<=≤<=100<=000, <=-<=109<=≤<=*k*<=≤<=109) — the number of books and the needed difference between the number of math problems and the number of economics problems. The second line contains *n* integers *t*1,<=*t*2,<=...,<=*t**n* (1<=≤<=*t**i*<=≤<=2), where *t**...
Print *q* lines, in the *i*-th of them print the number of subsegments for the *i*-th Ann's assumption.
[ "4 1\n1 1 1 2\n1 1 1 1\n4\n1 2\n1 3\n1 4\n3 4\n", "4 0\n1 2 1 2\n0 0 0 0\n1\n1 4\n" ]
[ "2\n3\n4\n1\n", "10\n" ]
In the first sample Ann can buy subsegments [1;1], [2;2], [3;3], [2;4] if they fall into the sales segment, because the number of math problems is greater by 1 on them that the number of economics problems. So we should count for each assumption the number of these subsegments that are subsegments of the given segment....
[ { "input": "4 1\n1 1 1 2\n1 1 1 1\n4\n1 2\n1 3\n1 4\n3 4", "output": "2\n3\n4\n1" }, { "input": "4 0\n1 2 1 2\n0 0 0 0\n1\n1 4", "output": "10" }, { "input": "10 10\n2 1 1 1 1 1 1 1 1 2\n0 10 10 0 0 10 10 10 10 0\n10\n4 10\n3 7\n9 9\n2 9\n10 10\n5 5\n2 2\n6 8\n3 4\n1 3", "output": "7...
0
0
-1
3,966
90
Cableway
[ "greedy", "math" ]
A. Cableway
2
256
A group of university students wants to get to the top of a mountain to have a picnic there. For that they decided to use a cableway. A cableway is represented by some cablecars, hanged onto some cable stations by a cable. A cable is scrolled cyclically between the first and the last cable stations (the first of them ...
The first line contains three integers *r*, *g* and *b* (0<=≤<=*r*,<=*g*,<=*b*<=≤<=100). It is guaranteed that *r*<=+<=*g*<=+<=*b*<=&gt;<=0, it means that the group consists of at least one student.
Print a single number — the minimal time the students need for the whole group to ascend to the top of the mountain.
[ "1 3 2\n", "3 2 1\n" ]
[ "34", "33" ]
Let's analyze the first sample. At the moment of time 0 a red cablecar comes and one student from the *r* group get on it and ascends to the top at the moment of time 30. At the moment of time 1 a green cablecar arrives and two students from the *g* group get on it; they get to the top at the moment of time 31. At t...
[ { "input": "1 3 2", "output": "34" }, { "input": "3 2 1", "output": "33" }, { "input": "3 5 2", "output": "37" }, { "input": "10 10 10", "output": "44" }, { "input": "29 7 24", "output": "72" }, { "input": "28 94 13", "output": "169" }, { "...
218
0
3.9455
3,971
85
Domino
[ "constructive algorithms", "implementation" ]
A. Domino
1
256
We all know the problem about the number of ways one can tile a 2<=×<=*n* field by 1<=×<=2 dominoes. You probably remember that it goes down to Fibonacci numbers. We will talk about some other problem below, there you also are going to deal with tiling a rectangular field with dominoes. You are given a 4<=×<=*n* recta...
The input contains one positive integer *n* (1<=≤<=*n*<=≤<=100) — the number of the field's columns.
If there's no solution, print "-1" (without the quotes). Otherwise, print four lines containing *n* characters each — that's the description of tiling, where each vertical cut intersects at least one domino. You should print the tiling, having painted the field in no more than 26 colors. Each domino should be painted a...
[ "4\n" ]
[ "yyzz\nbccd\nbxxd\nyyaa\n" ]
none
[ { "input": "4", "output": "aacc\nbbdd\nzkkz\nzllz" }, { "input": "2", "output": "aa\nbb\naa\nbb" }, { "input": "3", "output": "aab\nccb\nbaa\nbcc" }, { "input": "5", "output": "aaccz\nbbddz\nzkkmm\nzllnn" }, { "input": "1", "output": "a\na\nb\nb" }, { ...
248
512,000
0
3,979
31
Worms Evolution
[ "implementation" ]
A. Worms Evolution
2
256
Professor Vasechkin is studying evolution of worms. Recently he put forward hypotheses that all worms evolve by division. There are *n* forms of worms. Worms of these forms have lengths *a*1, *a*2, ..., *a**n*. To prove his theory, professor needs to find 3 different forms that the length of the first form is equal to ...
The first line contains integer *n* (3<=≤<=*n*<=≤<=100) — amount of worm's forms. The second line contains *n* space-separated integers *a**i* (1<=≤<=*a**i*<=≤<=1000) — lengths of worms of each form.
Output 3 distinct integers *i* *j* *k* (1<=≤<=*i*,<=*j*,<=*k*<=≤<=*n*) — such indexes of worm's forms that *a**i*<==<=*a**j*<=+<=*a**k*. If there is no such triple, output -1. If there are several solutions, output any of them. It possible that *a**j*<==<=*a**k*.
[ "5\n1 2 3 5 7\n", "5\n1 8 1 5 1\n" ]
[ "3 2 1\n", "-1\n" ]
none
[ { "input": "5\n1 2 3 5 7", "output": "3 2 1" }, { "input": "5\n1 8 1 5 1", "output": "-1" }, { "input": "4\n303 872 764 401", "output": "-1" }, { "input": "6\n86 402 133 524 405 610", "output": "6 4 1" }, { "input": "8\n217 779 418 895 996 473 3 22", "output":...
92
0
3.977
3,989
400
Inna and Choose Options
[ "implementation" ]
null
null
There always is something to choose from! And now, instead of "Noughts and Crosses", Inna choose a very unusual upgrade of this game. The rules of the game are given below: There is one person playing the game. Before the beginning of the game he puts 12 cards in a row on the table. Each card contains a character: "X"...
The first line of the input contains integer *t* (1<=≤<=*t*<=≤<=100). This value shows the number of sets of test data in the input. Next follows the description of each of the *t* tests on a separate line. The description of each test is a string consisting of 12 characters, each character is either "X", or "O". The ...
For each test, print the answer to the test on a single line. The first number in the line must represent the number of distinct ways to choose the pair *a*,<=*b*. Next, print on this line the pairs in the format *a*x*b*. Print the pairs in the order of increasing first parameter (*a*). Separate the pairs in the line b...
[ "4\nOXXXOXOOXOOX\nOXOXOXOXOXOX\nXXXXXXXXXXXX\nOOOOOOOOOOOO\n" ]
[ "3 1x12 2x6 4x3\n4 1x12 2x6 3x4 6x2\n6 1x12 2x6 3x4 4x3 6x2 12x1\n0\n" ]
none
[ { "input": "4\nOXXXOXOOXOOX\nOXOXOXOXOXOX\nXXXXXXXXXXXX\nOOOOOOOOOOOO", "output": "3 1x12 2x6 4x3\n4 1x12 2x6 3x4 6x2\n6 1x12 2x6 3x4 4x3 6x2 12x1\n0" }, { "input": "2\nOOOOOOOOOOOO\nXXXXXXXXXXXX", "output": "0\n6 1x12 2x6 3x4 4x3 6x2 12x1" }, { "input": "13\nXXXXXXXXXXXX\nXXXXXXXXXXXX\n...
77
0
3
3,992
181
Number of Triplets
[ "binary search", "brute force" ]
null
null
You are given *n* points on a plane. All points are different. Find the number of different groups of three points (*A*,<=*B*,<=*C*) such that point *B* is the middle of segment *AC*. The groups of three points are considered unordered, that is, if point *B* is the middle of segment *AC*, then groups (*A*,<=*B*,<=*C...
The first line contains a single integer *n* (3<=≤<=*n*<=≤<=3000) — the number of points. Next *n* lines contain the points. The *i*-th line contains coordinates of the *i*-th point: two space-separated integers *x**i*,<=*y**i* (<=-<=1000<=≤<=*x**i*,<=*y**i*<=≤<=1000). It is guaranteed that all given points are diff...
Print the single number — the answer to the problem.
[ "3\n1 1\n2 2\n3 3\n", "3\n0 0\n-1 0\n0 1\n" ]
[ "1\n", "0\n" ]
none
[ { "input": "3\n1 1\n2 2\n3 3", "output": "1" }, { "input": "3\n0 0\n-1 0\n0 1", "output": "0" }, { "input": "4\n0 0\n1 0\n2 0\n3 0", "output": "2" }, { "input": "5\n0 -1\n0 -2\n0 -3\n0 -4\n0 -5", "output": "4" }, { "input": "7\n1 1\n-1 -1\n1 0\n0 1\n-1 0\n0 -1\n0 ...
466
16,998,400
0
3,997
959
Mahmoud and Ehab and the even-odd game
[ "games", "math" ]
null
null
Mahmoud and Ehab play a game called the even-odd game. Ehab chooses his favorite integer *n* and then they take turns, starting from Mahmoud. In each player's turn, he has to choose an integer *a* and subtract it from *n* such that: - 1<=≤<=*a*<=≤<=*n*. - If it's Mahmoud's turn, *a* has to be even, but if it's Ehab'...
The only line contains an integer *n* (1<=≤<=*n*<=≤<=109), the number at the beginning of the game.
Output "Mahmoud" (without quotes) if Mahmoud wins and "Ehab" (without quotes) otherwise.
[ "1\n", "2\n" ]
[ "Ehab", "Mahmoud" ]
In the first sample, Mahmoud can't choose any integer *a* initially because there is no positive even integer less than or equal to 1 so Ehab wins. In the second sample, Mahmoud has to choose *a* = 2 and subtract it from *n*. It's Ehab's turn and *n* = 0. There is no positive odd integer less than or equal to 0 so Mah...
[ { "input": "1", "output": "Ehab" }, { "input": "2", "output": "Mahmoud" }, { "input": "10000", "output": "Mahmoud" }, { "input": "33333", "output": "Ehab" }, { "input": "5", "output": "Ehab" }, { "input": "1000000000", "output": "Mahmoud" }, { ...
0
0
-1
4,010
817
Treasure Hunt
[ "implementation", "math", "number theory" ]
null
null
Captain Bill the Hummingbird and his crew recieved an interesting challenge offer. Some stranger gave them a map, potion of teleportation and said that only this potion might help them to reach the treasure. Bottle with potion has two values *x* and *y* written on it. These values define four moves which can be perfo...
The first line contains four integer numbers *x*1,<=*y*1,<=*x*2,<=*y*2 (<=-<=105<=≤<=*x*1,<=*y*1,<=*x*2,<=*y*2<=≤<=105) — positions of Captain Bill the Hummingbird and treasure respectively. The second line contains two integer numbers *x*,<=*y* (1<=≤<=*x*,<=*y*<=≤<=105) — values on the potion bottle.
Print "YES" if it is possible for Captain to reach the treasure using the potion, otherwise print "NO" (without quotes).
[ "0 0 0 6\n2 3\n", "1 1 3 6\n1 5\n" ]
[ "YES\n", "NO\n" ]
In the first example there exists such sequence of moves: 1. <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/7c939890fb4ed35688177327dac981bfa9216c00.png" style="max-width: 100.0%;max-height: 100.0%;"/> — the first type of move 1. <img align="middle" class="tex-formula" src="https://espr...
[ { "input": "0 0 0 6\n2 3", "output": "YES" }, { "input": "1 1 3 6\n1 5", "output": "NO" }, { "input": "5 4 6 -10\n1 1", "output": "NO" }, { "input": "6 -3 -7 -7\n1 2", "output": "NO" }, { "input": "2 -5 -8 8\n2 1", "output": "YES" }, { "input": "70 -81...
109
307,200
3
4,028
380
Sereja and Brackets
[ "data structures", "schedules" ]
null
null
Sereja has a bracket sequence *s*1,<=*s*2,<=...,<=*s**n*, or, in other words, a string *s* of length *n*, consisting of characters "(" and ")". Sereja needs to answer *m* queries, each of them is described by two integers *l**i*,<=*r**i* (1<=≤<=*l**i*<=≤<=*r**i*<=≤<=*n*). The answer to the *i*-th query is the length o...
The first line contains a sequence of characters *s*1,<=*s*2,<=...,<=*s**n* (1<=≤<=*n*<=≤<=106) without any spaces. Each character is either a "(" or a ")". The second line contains integer *m* (1<=≤<=*m*<=≤<=105) — the number of queries. Each of the next *m* lines contains a pair of integers. The *i*-th line contains ...
Print the answer to each question on a single line. Print the answers in the order they go in the input.
[ "())(())(())(\n7\n1 1\n2 3\n1 2\n1 12\n8 12\n5 11\n2 10\n" ]
[ "0\n0\n2\n10\n4\n6\n6\n" ]
A subsequence of length |*x*| of string *s* = *s*<sub class="lower-index">1</sub>*s*<sub class="lower-index">2</sub>... *s*<sub class="lower-index">|*s*|</sub> (where |*s*| is the length of string *s*) is string *x* = *s*<sub class="lower-index">*k*<sub class="lower-index">1</sub></sub>*s*<sub class="lower-index">*k*<s...
[ { "input": "())(())(())(\n7\n1 1\n2 3\n1 2\n1 12\n8 12\n5 11\n2 10", "output": "0\n0\n2\n10\n4\n6\n6" }, { "input": "(((((()((((((((((()((()(((((\n1\n8 15", "output": "0" }, { "input": "((()((())(((((((((()(()(()(((((((((((((((()(()((((((((((((((()(((((((((((((((((((()(((\n39\n28 56\n39 ...
1,000
139,571,200
0
4,039
237
Primes on Interval
[ "binary search", "number theory", "two pointers" ]
null
null
You've decided to carry out a survey in the theory of prime numbers. Let us remind you that a prime number is a positive integer that has exactly two distinct positive integer divisors. Consider positive integers *a*, *a*<=+<=1, ..., *b* (*a*<=≤<=*b*). You want to find the minimum integer *l* (1<=≤<=*l*<=≤<=*b*<=-<=*a...
A single line contains three space-separated integers *a*,<=*b*,<=*k* (1<=≤<=*a*,<=*b*,<=*k*<=≤<=106; *a*<=≤<=*b*).
In a single line print a single integer — the required minimum *l*. If there's no solution, print -1.
[ "2 4 2\n", "6 13 1\n", "1 4 3\n" ]
[ "3\n", "4\n", "-1\n" ]
none
[ { "input": "2 4 2", "output": "3" }, { "input": "6 13 1", "output": "4" }, { "input": "1 4 3", "output": "-1" }, { "input": "5 8 2", "output": "4" }, { "input": "8 10 3", "output": "-1" }, { "input": "1 5 2", "output": "3" }, { "input": "6 ...
61
6,963,200
0
4,047
548
Mike and Fun
[ "brute force", "dp", "greedy", "implementation" ]
null
null
Mike and some bears are playing a game just for fun. Mike is the judge. All bears except Mike are standing in an *n*<=×<=*m* grid, there's exactly one bear in each cell. We denote the bear standing in column number *j* of row number *i* by (*i*,<=*j*). Mike's hands are on his ears (since he's the judge) and each bear s...
The first line of input contains three integers *n*, *m* and *q* (1<=≤<=*n*,<=*m*<=≤<=500 and 1<=≤<=*q*<=≤<=5000). The next *n* lines contain the grid description. There are *m* integers separated by spaces in each line. Each of these numbers is either 0 (for mouth) or 1 (for eyes). The next *q* lines contain the inf...
After each round, print the current score of the bears.
[ "5 4 5\n0 1 1 0\n1 0 0 1\n0 1 1 0\n1 0 0 1\n0 0 0 0\n1 1\n1 4\n1 1\n4 2\n4 3\n" ]
[ "3\n4\n3\n3\n4\n" ]
none
[ { "input": "5 4 5\n0 1 1 0\n1 0 0 1\n0 1 1 0\n1 0 0 1\n0 0 0 0\n1 1\n1 4\n1 1\n4 2\n4 3", "output": "3\n4\n3\n3\n4" }, { "input": "2 2 10\n1 1\n0 1\n1 1\n2 1\n1 1\n2 2\n1 1\n2 1\n2 2\n2 2\n1 1\n1 1", "output": "1\n2\n2\n2\n1\n1\n1\n1\n2\n1" }, { "input": "2 2 10\n1 1\n0 1\n2 2\n2 2\n1 1\...
46
102,400
0
4,049
833
The Meaningless Game
[ "math", "number theory" ]
null
null
Slastyona and her loyal dog Pushok are playing a meaningless game that is indeed very interesting. The game consists of multiple rounds. Its rules are very simple: in each round, a natural number *k* is chosen. Then, the one who says (or barks) it faster than the other wins the round. After that, the winner's score is...
In the first string, the number of games *n* (1<=≤<=*n*<=≤<=350000) is given. Each game is represented by a pair of scores *a*, *b* (1<=≤<=*a*,<=*b*<=≤<=109) – the results of Slastyona and Pushok, correspondingly.
For each pair of scores, answer "Yes" if it's possible for a game to finish with given score, and "No" otherwise. You can output each letter in arbitrary case (upper or lower).
[ "6\n2 4\n75 45\n8 8\n16 16\n247 994\n1000000000 1000000\n" ]
[ "Yes\nYes\nYes\nNo\nNo\nYes\n" ]
First game might have been consisted of one round, in which the number 2 would have been chosen and Pushok would have won. The second game needs exactly two rounds to finish with such result: in the first one, Slastyona would have said the number 5, and in the second one, Pushok would have barked the number 3.
[ { "input": "6\n2 4\n75 45\n8 8\n16 16\n247 994\n1000000000 1000000", "output": "Yes\nYes\nYes\nNo\nNo\nYes" }, { "input": "3\n1 1\n8 27\n1000 1331", "output": "Yes\nNo\nNo" }, { "input": "1\n12004 18012002", "output": "Yes" }, { "input": "1\n3331 11095561", "output": "Yes...
1,000
0
0
4,052
596
Wilbur and Points
[ "combinatorics", "greedy", "sortings" ]
null
null
Wilbur is playing with a set of *n* points on the coordinate plane. All points have non-negative integer coordinates. Moreover, if some point (*x*, *y*) belongs to the set, then all points (*x*', *y*'), such that 0<=≤<=*x*'<=≤<=*x* and 0<=≤<=*y*'<=≤<=*y* also belong to this set. Now Wilbur wants to number the points i...
The first line of the input consists of a single integer *n* (1<=≤<=*n*<=≤<=100<=000) — the number of points in the set Wilbur is playing with. Next follow *n* lines with points descriptions. Each line contains two integers *x* and *y* (0<=≤<=*x*,<=*y*<=≤<=100<=000), that give one point in Wilbur's set. It's guarantee...
If there exists an aesthetically pleasant numbering of points in the set, such that *s*(*x**i*,<=*y**i*)<==<=*y**i*<=-<=*x**i*<==<=*w**i*, then print "YES" on the first line of the output. Otherwise, print "NO". If a solution exists, proceed output with *n* lines. On the *i*-th of these lines print the point of the se...
[ "5\n2 0\n0 0\n1 0\n1 1\n0 1\n0 -1 -2 1 0\n", "3\n1 0\n0 0\n2 0\n0 1 2\n" ]
[ "YES\n0 0\n1 0\n2 0\n0 1\n1 1\n", "NO\n" ]
In the first sample, point (2, 0) gets number 3, point (0, 0) gets number one, point (1, 0) gets number 2, point (1, 1) gets number 5 and point (0, 1) gets number 4. One can easily check that this numbering is aesthetically pleasing and *y*<sub class="lower-index">*i*</sub> - *x*<sub class="lower-index">*i*</sub> = *w*...
[ { "input": "5\n2 0\n0 0\n1 0\n1 1\n0 1\n0 -1 -2 1 0", "output": "YES\n0 0\n1 0\n2 0\n0 1\n1 1" }, { "input": "3\n1 0\n0 0\n2 0\n0 1 2", "output": "NO" }, { "input": "9\n0 0\n1 0\n2 0\n0 1\n1 1\n2 1\n1 2\n2 2\n0 2\n0 0 0 -1 -1 -2 1 1 2", "output": "NO" }, { "input": "18\n0 0\n...
46
0
0
4,054
0
none
[ "none" ]
null
null
На координатной прямой сидит *n* собачек, *i*-я собачка находится в точке *x**i*. Кроме того, на прямой есть *m* мисок с едой, для каждой известна её координата на прямой *u**j* и время *t**j*, через которое еда в миске остынет и станет невкусной. Это значит, что если собачка прибежит к миске в момент времени, строго б...
В первой строке находится пара целых чисел *n* и *m* (1<=≤<=*n*,<=*m*<=≤<=200<=000) — количество собачек и мисок соответственно. Во второй строке находятся *n* целых чисел *x**i* (<=-<=109<=≤<=*x**i*<=≤<=109) — координата *i*-й собачки. В следующих *m* строках находятся пары целых чисел *u**j* и *t**j* (<=-<=109<=≤<=...
Выведите одно целое число *a* — максимальное количество собачек, которые смогут покушать.
[ "5 4\n-2 0 4 8 13\n-1 1\n4 3\n6 3\n11 2\n", "3 3\n-1 3 7\n1 1\n4 1\n7 1\n", "4 4\n20 1 10 30\n1 1\n2 5\n22 2\n40 10\n" ]
[ "4\n", "2\n", "3\n" ]
В первом примере первая собачка побежит направо к первой миске, третья собачка сразу начнёт есть из второй миски, четвёртая собачка побежит влево к третьей миске, а пятая собачка побежит влево к четвёртой миске.
[]
2,000
25,907,200
0
4,089
847
University Classes
[ "implementation" ]
null
null
There are *n* student groups at the university. During the study day, each group can take no more than 7 classes. Seven time slots numbered from 1 to 7 are allocated for the classes. The schedule on Monday is known for each group, i. e. time slots when group will have classes are known. Your task is to determine the ...
The first line contains a single integer *n* (1<=≤<=*n*<=≤<=1000) — the number of groups. Each of the following *n* lines contains a sequence consisting of 7 zeroes and ones — the schedule of classes on Monday for a group. If the symbol in a position equals to 1 then the group has class in the corresponding time slot...
Print minimum number of rooms needed to hold all groups classes on Monday.
[ "2\n0101010\n1010101\n", "3\n0101011\n0011001\n0110111\n" ]
[ "1\n", "3\n" ]
In the first example one room is enough. It will be occupied in each of the seven time slot by the first group or by the second group. In the second example three rooms is enough, because in the seventh time slot all three groups have classes.
[ { "input": "2\n0101010\n1010101", "output": "1" }, { "input": "3\n0101011\n0011001\n0110111", "output": "3" }, { "input": "1\n0111000", "output": "1" }, { "input": "1\n0000000", "output": "0" }, { "input": "1\n1111111", "output": "1" }, { "input": "2\n...
109
3,481,600
3
4,090
124
Permutations
[ "brute force", "combinatorics", "implementation" ]
null
null
You are given *n* *k*-digit integers. You have to rearrange the digits in the integers so that the difference between the largest and the smallest number was minimum. Digits should be rearranged by the same rule in all integers.
The first line contains integers *n* and *k* — the number and digit capacity of numbers correspondingly (1<=≤<=*n*,<=*k*<=≤<=8). Next *n* lines contain *k*-digit positive integers. Leading zeroes are allowed both in the initial integers and the integers resulting from the rearranging of digits.
Print a single number: the minimally possible difference between the largest and the smallest number after the digits are rearranged in all integers by the same rule.
[ "6 4\n5237\n2753\n7523\n5723\n5327\n2537\n", "3 3\n010\n909\n012\n", "7 5\n50808\n36603\n37198\n44911\n29994\n42543\n50156\n" ]
[ "2700\n", "3\n", "20522\n" ]
In the first sample, if we rearrange the digits in numbers as (3,1,4,2), then the 2-nd and the 4-th numbers will equal 5237 and 2537 correspondingly (they will be maximum and minimum for such order of digits). In the second sample, if we swap the second digits and the first ones, we get integers 100, 99 and 102.
[ { "input": "6 4\n5237\n2753\n7523\n5723\n5327\n2537", "output": "2700" }, { "input": "3 3\n010\n909\n012", "output": "3" }, { "input": "7 5\n50808\n36603\n37198\n44911\n29994\n42543\n50156", "output": "20522" }, { "input": "5 5\n61374\n74304\n41924\n46010\n09118", "output...
122
2,867,200
-1
4,106
704
Ant Man
[ "dp", "graphs", "greedy" ]
null
null
Scott Lang is at war with Darren Cross. There are *n* chairs in a hall where they are, numbered with 1,<=2,<=...,<=*n* from left to right. The *i*-th chair is located at coordinate *x**i*. Scott is on chair number *s* and Cross is on chair number *e*. Scott can jump to all other chairs (not only neighboring chairs). He...
The first line of the input contains three integers *n*,<=*s* and *e* (2<=≤<=*n*<=≤<=5000,<=1<=≤<=*s*,<=*e*<=≤<=*n*,<=*s*<=≠<=*e*) — the total number of chairs, starting and ending positions of Scott. The second line contains *n* integers *x*1,<=*x*2,<=...,<=*x**n* (1<=≤<=*x*1<=&lt;<=*x*2<=&lt;<=...<=&lt;<=*x**n*<=≤<=...
Print the minimum amount of time Scott needs to get to the Cross while visiting each chair exactly once.
[ "7 4 3\n8 11 12 16 17 18 20\n17 16 20 2 20 5 13\n17 8 8 16 12 15 13\n12 4 16 4 15 7 6\n8 14 2 11 17 12 8\n" ]
[ "139\n" ]
In the sample testcase, an optimal solution would be <img align="middle" class="tex-formula" src="https://espresso.codeforces.com/5bbd3e094ffa5a72e263dfaec7aeaff795bc22a3.png" style="max-width: 100.0%;max-height: 100.0%;"/>. Spent time would be 17 + 24 + 23 + 20 + 33 + 22 = 139.
[ { "input": "7 4 3\n8 11 12 16 17 18 20\n17 16 20 2 20 5 13\n17 8 8 16 12 15 13\n12 4 16 4 15 7 6\n8 14 2 11 17 12 8", "output": "139" }, { "input": "2 1 2\n75475634 804928248\n476927808 284875072\n503158867 627937890\n322595515 786026685\n645468307 669240390", "output": "1659795993" }, { ...
46
512,000
0
4,107
523
Rotate, Flip and Zoom
[ "*special", "implementation" ]
null
null
Polycarp is writing the prototype of a graphic editor. He has already made up his mind that the basic image transformations in his editor will be: rotate the image 90 degrees clockwise, flip the image horizontally (symmetry relative to the vertical line, that is, the right part of the image moves to the left, and vice ...
The first line contains two integers, *w* and *h* (1<=≤<=*w*,<=*h*<=≤<=100) — the width and height of an image in pixels. The picture is given in *h* lines, each line contains *w* characters — each character encodes the color of the corresponding pixel of the image. The line consists only of characters "." and "*", as ...
Print 2*w* lines, each containing 2*h* characters — the result of consecutive implementing of the three transformations, described above.
[ "3 2\n.*.\n.*.\n", "9 20\n**.......\n****.....\n******...\n*******..\n..******.\n....****.\n......***\n*.....***\n*********\n*********\n*********\n*********\n....**...\n...****..\n..******.\n.********\n****..***\n***...***\n**.....**\n*.......*\n" ]
[ "....\n....\n****\n****\n....\n....\n", "********......**********........********\n********......**********........********\n********........********......********..\n********........********......********..\n..********......********....********....\n..********......********....********....\n..********......*****...
none
[ { "input": "3 2\n.*.\n.*.", "output": "....\n....\n****\n****\n....\n...." }, { "input": "9 20\n**.......\n****.....\n******...\n*******..\n..******.\n....****.\n......***\n*.....***\n*********\n*********\n*********\n*********\n....**...\n...****..\n..******.\n.********\n****..***\n***...***\n**.......
62
102,400
3
4,108
929
Прокат велосипедов
[ "*special", "greedy", "implementation" ]
null
null
Как известно, в теплую погоду многие жители крупных городов пользуются сервисами городского велопроката. Вот и Аркадий сегодня будет добираться от школы до дома, используя городские велосипеды. Школа и дом находятся на одной прямой улице, кроме того, на той же улице есть *n* точек, где можно взять велосипед в прокат и...
В первой строке следуют два целых числа *n* и *k* (2<=≤<=*n*<=≤<=1<=000, 1<=≤<=*k*<=≤<=100<=000) — количество велопрокатов и максимальное расстояние, которое Аркадий может проехать на одном велосипеде. В следующей строке следует последовательность целых чисел *x*1,<=*x*2,<=...,<=*x**n* (0<=≤<=*x*1<=&lt;<=*x*2<=&lt;<=....
Если Аркадий не сможет добраться от школы до дома только на велосипедах, выведите -1. В противном случае, выведите минимальное количество велосипедов, которые Аркадию нужно взять в точках проката.
[ "4 4\n3 6 8 10\n", "2 9\n10 20\n", "12 3\n4 6 7 9 10 11 13 15 17 18 20 21\n" ]
[ "2\n", "-1\n", "6\n" ]
В первом примере Аркадий должен взять первый велосипед в первом велопрокате и доехать на нём до второго велопроката. Во втором велопрокате он должен взять новый велосипед, на котором он сможет добраться до четвертого велопроката, рядом с которым и находится его дом. Поэтому Аркадию нужно всего два велосипеда, чтобы доб...
[ { "input": "4 4\n3 6 8 10", "output": "2" }, { "input": "2 9\n10 20", "output": "-1" }, { "input": "12 3\n4 6 7 9 10 11 13 15 17 18 20 21", "output": "6" }, { "input": "2 1\n11164 11165", "output": "1" }, { "input": "3 7\n45823 45825 45829", "output": "1" },...
62
5,632,000
3
4,119
895
String Mark
[ "combinatorics", "math", "strings" ]
null
null
At the Byteland State University marks are strings of the same length. Mark *x* is considered better than *y* if string *y* is lexicographically smaller than *x*. Recently at the BSU was an important test work on which Vasya recived the mark *a*. It is very hard for the teacher to remember the exact mark of every stud...
First line contains string *a*, second line contains string *b*. Strings *a*,<=*b* consist of lowercase English letters. Their lengths are equal and don't exceed 106. It is guaranteed that *a* is lexicographically smaller than *b*.
Print one integer  — the number of different strings satisfying the condition of the problem modulo 109<=+<=7.
[ "abc\nddd\n", "abcdef\nabcdeg\n", "abacaba\nubuduba\n" ]
[ "5\n", "0\n", "64\n" ]
In first sample from string *abc* can be obtained strings *acb*, *bac*, *bca*, *cab*, *cba*, all of them are larger than *abc*, but smaller than *ddd*. So the answer is 5. In second sample any string obtained from *abcdef* is larger than *abcdeg*. So the answer is 0.
[ { "input": "abc\nddd", "output": "5" }, { "input": "abcdef\nabcdeg", "output": "0" }, { "input": "abacaba\nubuduba", "output": "64" }, { "input": "aac\nbbb", "output": "1" }, { "input": "aaaccc\nbbbbbb", "output": "9" }, { "input": "aaaaaa\nzzzzzz", ...
4,000
43,315,200
0
4,127
207
The Beaver's Problem - 3
[]
null
null
The Smart Beaver from ABBYY came up with another splendid problem for the ABBYY Cup participants! This time the Beaver invites the contest participants to check out a problem on sorting documents by their subjects. Let's describe the problem: You've got some training set of documents. For each document you know its su...
The first line contains integer *id* (0<=≤<=*id*<=≤<=106) — the document identifier. The second line contains the name of the document. The third and the subsequent lines contain the text of the document. It is guaranteed that the size of any given document will not exceed 10 kilobytes. The tests for this problem are ...
Print an integer from 1 to 3, inclusive — the number of the subject the given document corresponds to.
[]
[]
none
[ { "input": "2000\nJAPAN FEBRUARY MONEY SUPPLY RISES 8.8 PCT\nTOKYO, March 17 - Japan's broadly defined money supply\naverage of M-2 plus certificate of deposits (CDs) rose a\npreliminary 8.8 pct in February from a year earlier, compared\nwith an 8.6 pct rise in January, the Bank of Japan said.\nThe seasonally a...
31
0
0
4,146
535
Tavas and Nafas
[ "brute force", "implementation" ]
null
null
Today Tavas got his test result as an integer score and he wants to share it with his girlfriend, Nafas. His phone operating system is Tavdroid, and its keyboard doesn't have any digits! He wants to share his score with Nafas via text, so he has no choice but to send this number using words. He ate coffee mix without...
The first and only line of input contains an integer *s* (0<=≤<=*s*<=≤<=99), Tavas's score.
In the first and only line of output, print a single string consisting only from English lowercase letters and hyphens ('-'). Do not use spaces.
[ "6\n", "99\n", "20\n" ]
[ "six\n", "ninety-nine\n", "twenty\n" ]
You can find all you need to know about English numerals in [http://en.wikipedia.org/wiki/English_numerals](https://en.wikipedia.org/wiki/English_numerals) .
[ { "input": "6", "output": "six" }, { "input": "99", "output": "ninety-nine" }, { "input": "20", "output": "twenty" }, { "input": "10", "output": "ten" }, { "input": "15", "output": "fifteen" }, { "input": "27", "output": "twenty-seven" }, { ...
124
307,200
3
4,167
464
The Classic Problem
[ "data structures", "graphs", "shortest paths" ]
null
null
You are given a weighted undirected graph on *n* vertices and *m* edges. Find the shortest path from vertex *s* to vertex *t* or else state that such path doesn't exist.
The first line of the input contains two space-separated integers — *n* and *m* (1<=≤<=*n*<=≤<=105; 0<=≤<=*m*<=≤<=105). Next *m* lines contain the description of the graph edges. The *i*-th line contains three space-separated integers — *u**i*, *v**i*, *x**i* (1<=≤<=*u**i*,<=*v**i*<=≤<=*n*; 0<=≤<=*x**i*<=≤<=105). That...
In the first line print the remainder after dividing the length of the shortest path by 1000000007 (109<=+<=7) if the path exists, and -1 if the path doesn't exist. If the path exists print in the second line integer *k* — the number of vertices in the shortest path from vertex *s* to vertex *t*; in the third line pri...
[ "4 4\n1 4 2\n1 2 0\n2 3 0\n3 4 0\n1 4\n", "4 3\n1 2 4\n2 3 5\n3 4 6\n1 4\n", "4 2\n1 2 0\n3 4 1\n1 4\n" ]
[ "3\n4\n1 2 3 4 \n", "112\n4\n1 2 3 4 \n", "-1\n" ]
A path from vertex *s* to vertex *t* is a sequence *v*<sub class="lower-index">0</sub>, ..., *v*<sub class="lower-index">*k*</sub>, such that *v*<sub class="lower-index">0</sub> = *s*, *v*<sub class="lower-index">*k*</sub> = *t*, and for any *i* from 0 to *k* - 1 vertices *v*<sub class="lower-index">*i*</sub> and *v*<s...
[]
5,000
3,584,000
0
4,168
686
Little Robber Girl's Zoo
[ "constructive algorithms", "implementation", "sortings" ]
null
null
Little Robber Girl likes to scare animals in her zoo for fun. She decided to arrange the animals in a row in the order of non-decreasing height. However, the animals were so scared that they couldn't stay in the right places. The robber girl was angry at first, but then she decided to arrange the animals herself. She ...
The first line contains a single integer *n* (1<=≤<=*n*<=≤<=100) — number of animals in the robber girl's zoo. The second line contains *n* space-separated integers *a*1,<=*a*2,<=...,<=*a**n* (1<=≤<=*a**i*<=≤<=109), where *a**i* is the height of the animal occupying the *i*-th place.
Print the sequence of operations that will rearrange the animals by non-decreasing height. The output should contain several lines, *i*-th of the lines should contain two space-separated integers *l**i* and *r**i* (1<=≤<=*l**i*<=&lt;<=*r**i*<=≤<=*n*) — descriptions of segments the robber girl should name. The segments...
[ "4\n2 1 4 3\n", "7\n36 28 57 39 66 69 68\n", "5\n1 2 1 2 1\n" ]
[ "1 4\n", "1 4\n6 7\n", "2 5\n3 4\n1 4\n1 4\n" ]
Note that you don't have to minimize the number of operations. Any solution that performs at most 20 000 operations is allowed.
[ { "input": "4\n2 1 4 3", "output": "1 2\n3 4" }, { "input": "7\n36 28 57 39 66 69 68", "output": "1 2\n3 4\n6 7" }, { "input": "5\n1 2 1 2 1", "output": "2 3\n4 5\n3 4" }, { "input": "78\n7 3 8 8 9 8 10 9 12 11 16 14 17 17 18 18 20 20 25 22 27 26 29 27 35 35 36 36 37 37 38 38...
140
4,300,800
3
4,173
761
Dasha and friends
[ "brute force", "implementation", "math" ]
null
null
Running with barriers on the circle track is very popular in the country where Dasha lives, so no wonder that on her way to classes she saw the following situation: The track is the circle with length *L*, in distinct points of which there are *n* barriers. Athlete always run the track in counterclockwise direction if...
The first line contains two integers *n* and *L* (1<=≤<=*n*<=≤<=50, *n*<=≤<=*L*<=≤<=100) — the number of barriers on a track and its length. The second line contains *n* distinct integers in the ascending order — the distance from Kefa's start to each barrier in the order of its appearance. All integers are in the ra...
Print "YES" (without quotes), if Kefa and Sasha ran the coinciding tracks (it means that the position of all barriers coincides, if they start running from the same points on the track). Otherwise print "NO" (without quotes).
[ "3 8\n2 4 6\n1 5 7\n", "4 9\n2 3 5 8\n0 1 3 6\n", "2 4\n1 3\n1 2\n" ]
[ "YES\n", "YES\n", "NO\n" ]
The first test is analyzed in the statement.
[ { "input": "3 8\n2 4 6\n1 5 7", "output": "YES" }, { "input": "4 9\n2 3 5 8\n0 1 3 6", "output": "YES" }, { "input": "2 4\n1 3\n1 2", "output": "NO" }, { "input": "5 9\n0 2 5 6 7\n1 3 6 7 8", "output": "YES" }, { "input": "5 60\n7 26 27 40 59\n14 22 41 42 55", ...
46
4,608,000
0
4,181
253
Text Editor
[ "data structures", "dfs and similar", "graphs", "greedy", "shortest paths" ]
null
null
Vasya is pressing the keys on the keyboard reluctantly, squeezing out his ideas on the classical epos depicted in Homer's Odysseus... How can he explain to his literature teacher that he isn't going to become a writer? In fact, he is going to become a programmer. So, he would take great pleasure in writing a program, b...
The first line of the input contains an integer *n* (1<=≤<=*n*<=≤<=100) — the number of lines in the file. The second line contains *n* integers *a*1,<=*a*2,<=...,<=*a**n* (0<=≤<=*a**i*<=≤<=105), separated by single spaces. The third line contains four integers *r*1,<=*c*1,<=*r*2,<=*c*2 (1<=≤<=*r*1,<=*r*2<=≤<=*n*,<=1<=...
Print a single integer — the minimum number of times Vasya should push a key to move the cursor from position (*r*1,<=*c*1) to position (*r*2,<=*c*2).
[ "4\n2 1 6 4\n3 4 4 2\n", "4\n10 5 6 4\n1 11 4 2\n", "3\n10 1 10\n1 10 1 1\n" ]
[ "3\n", "6\n", "3\n" ]
In the first sample the editor contains four lines. Let's represent the cursor's possible positions in the line as numbers. Letter *s* represents the cursor's initial position, letter *t* represents the last one. Then all possible positions of the cursor in the text editor are described by the following table. 123 12...
[ { "input": "4\n2 1 6 4\n3 4 4 2", "output": "3" }, { "input": "4\n10 5 6 4\n1 11 4 2", "output": "6" }, { "input": "3\n10 1 10\n1 10 1 1", "output": "3" }, { "input": "4\n2 1 6 4\n4 2 3 5", "output": "4" }, { "input": "3\n20 3 20\n1 20 1 1", "output": "5" },...
186
409,600
0
4,182
234
Lefthanders and Righthanders
[ "implementation" ]
null
null
One fine October day a mathematics teacher Vasily Petrov went to a class and saw there *n* pupils who sat at the desks, two people at each desk. Vasily quickly realized that number *n* is even. Like all true mathematicians, Vasily has all students numbered from 1 to *n*. But Vasily Petrov did not like the way the chi...
The first input line contains a single even integer *n* (4<=≤<=*n*<=≤<=100) — the number of students in the class. The second line contains exactly *n* capital English letters "L" and "R". If the *i*-th letter at the second line equals "L", then the student number *i* is a lefthander, otherwise he is a righthander.
Print integer pairs, one pair per line. In the *i*-th line print the numbers of students that will sit at the *i*-th desk. The first number in the pair stands for the student who is sitting to the left, and the second number stands for the student who is sitting to the right. Separate the numbers in the pairs by space...
[ "6\nLLRLLL\n", "4\nRRLL\n" ]
[ "1 4\n2 5\n6 3\n", "3 1\n4 2\n" ]
none
[ { "input": "6\nLLRLLL", "output": "1 4\n2 5\n6 3" }, { "input": "4\nRRLL", "output": "3 1\n4 2" }, { "input": "4\nLLRR", "output": "1 3\n2 4" }, { "input": "6\nRLLRRL", "output": "1 4\n2 5\n3 6" }, { "input": "8\nLRLRLLLR", "output": "1 5\n6 2\n3 7\n4 8" }, ...
46
6,656,000
-1
4,186