题目传送门 /* 题意:某几列的数字翻转,使得某些行全为1,求出最多能有几行 想了好久都没有思路,看了代码才知道不用蠢办法,匹配初始相同的行最多能有几对就好了,不必翻转 */ #include <cstdio> #include <algorithm> #include <string> #include <cmath> #include <iostream> using namespace std; ; const int INF = 0x3f…

题目传送门 /* 找规律,水 */ #include <cstdio> #include <iostream> #include <algorithm> #include <cstring> #include <cmath> using namespace std; ; const int INF = 0x3f3f3f3f; ]; int main(void) //Codeforces Round #309 (Div. 2) A. Kyoya a…

C. Love Triangles Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/553/problem/C Description There are many anime that are about "love triangles": Alice loves Bob, and Charlie loves Bob as well, but Alice hates Charlie.…

B. Kyoya and Permutation Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/553/problem/B Description Let's define the permutation of length n as an array p = [p1, p2, ..., pn] consisting of n distinct integers from range from…

C. Kyoya and Colored Balls Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/C Description Kyoya Ootori has a bag with n colored balls that are colored with k different colors. The colors are labeled from 1 to k.…

B. Ohana Cleans Up Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/B Description Ohana Matsumae is trying to clean a room, which is divided up into an n by n grid of squares. Each square is initially either clea…

A. Kyoya and Photobooks Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/554/problem/A Description Kyoya Ootori is selling photobooks of the Ouran High School Host Club. He has 26 photos, labeled "a" to "z", a…

C. Kyoya and Colored Balls Kyoya Ootori has a bag with n colored balls that are colored with k different colors. The colors are labeled from 1 to k. Balls of the same color are indistinguishable. He draws balls from the bag one by one until the bag i…

A. Kyoya and Photobooks Kyoya Ootori is selling photobooks of the Ouran High School Host Club. He has 26 photos, labeled "a" to "z", and he has compiled them into a photo booklet with some photos in some order (possibly with some photo…

题目:http://codeforces.com/contest/553/problem/A 题意:给你k个颜色的球,下面k行代表每个颜色的球有多少个,规定第i种颜色的球的最后一个在第i-1种颜色的球的最后一个的前面 思路:首先我们想如果是第i种颜色,我们首先必须把这个颜色留下一个,留下的这个球前面的球的个数是前面颜色的总和+这个颜色数-1, 我们想这个颜色的位置数如何安排,即 C(总座位数,要安排的个数),i-1种颜色也是相同的道理,所以我们推出公式 累加球的个数 sum 当前颜色的球的个数n…