time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output Petr wants to make a calendar for current month. For this purpose he draws a table in which columns correspond to weeks (a week is seven consequ…
题目链接:http://codeforces.com/problemset/problem/331/C1 这是第一次参加codeforces比赛(ABBYY Cup 3.0 - Finals (online version))成功AC的题目(n ≤ 106),解题的突破口是:Take the magic number, subtract a digit from it (the digit must occur in the number) and get a new magic number.…
题目链接:http://codeforces.com/problemset/problem/113/B 题目大意: 多组数据每组给定3个字符串T,Sbeg,Sed,求字符串T中有多少子串是以Sbeg开头,Sed结尾的 分析: 难点在哈希函数的编写,如果直接存string会爆内存,不能用STL自带哈希函数,用了会Wa. 代码如下: #include <bits/stdc++.h> using namespace std; #define rep(i,n) for (int i = 0; i &l…
题目连接: Petr and Permutations 题意:给出一个1到n的序列,Petr打乱了3n次,Um_nik打乱了7n+1次,现在给出被打乱后的序列,求是谁打乱的. 题解:因为给出了一个3*n和一个7*n+1,发现这两个当一个为奇数另一个一定为偶数,所以可以联想和奇偶性质有关.但是这里面要算最短几步能把当前的序列变成1-n.这里我算错~~顺便学了一下如何将置换序列复原. #include<bits/stdc++.h> using namespace std; typedef pair…
time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output You are given names of two days of the week. Please, determine whether it is possible that during some non-leap year the first day of some month…
Description\text{Description}Description Given an array a[], swap random 2 number of them for 3n or (7n+1) times.\text{Given an array }a[],\text{ swap random 2 number of them for }3n\text{ or }(7n+1)\text{ times.}Given an array a[], swap random 2 num…
