题目大意 两个人轮流在一个字符串上删掉一个字符,没有字符可删的人输掉游戏 删字符的规则如下: 1. 每次从一个字符串中选取一个字符,它是一个长度至少为 3 的奇回文串的中心 2. 删掉该字符,同时,他选择的那个字符串分成了两个独立的字符串 现在问,先手是否必胜,如果先手必胜,输出第一步应该删掉第几个字符,有多解的话,输出序号最小的那个 字符串的长度不超过5000,只包含小写英文字母 做法分析 可以这样考虑:将所有的长度大于等于 3(其实只需要找长度为 3 的就行)的奇回文串的中心标记出来 我们将…

Codeforces Round #297 (Div. 2)B. Pasha and String Time Limit: 2 Sec  Memory Limit: 256 MBSubmit: xxx  Solved: 2xx 题目连接 http://codeforces.com/contest/525/problem/B Description Pasha got a very beautiful string s for his birthday, the string consists o…

题目传送门 /* 题意:给出m个位置,每次把[p,len-p+1]内的字符子串反转,输出最后的结果 字符串处理:朴素的方法超时,想到结果要么是反转要么没有反转,所以记录 每个转换的次数,把每次要反转的反转就不超时了:) */ #include <cstdio> #include <algorithm> #include <cstring> using namespace std; ; const int INF = 0x3f3f3f3f; char s[MAXN]; i…

A. Strange Addition (目前的做法好像做烦了) 统计数的\(mask\),表示个.十.百位上是否是0,共8种数. 枚举8种数组成的所有情况\(2^8\),记录最大数量. B. Continued Fractions 大数.分数运算. C. Ivan and Powers of Two \(map\)模拟即可. D. Olya and Graph \(i\)和\(i+1\)必然连边. \(i\)要连第二条边的话,只能连向\(i+k+1\),并且对于\(j\ge i+k+1\)不能…

题目链接:http://codeforces.com/contest/877/problem/B Nikita and string time limit per test2 seconds memory limit per test256 megabytes Nikita thinks that string is beautiful if it can be cut into 3 strings (possibly empty) without changing the order of t…

C. Playing Piano 题目链接:https://codeforces.com/contest/1079/problem/C 题意: 给出数列{an},现在要求你给出一个数列{bn},满足: 1.当an+1>an时,有bn+1>bn:2.当an+1=an时,有bn+1!=bn:3.当an+1<an时,有bn+1<bn. 且满足1<=bn<=5. 题解: 我们可以考虑动态规划,设dp(i,j)为第i位置时,b(i)=j是否可行. 那么状态转移时可以分ai>…

A. Playing with Paper One day Vasya was sitting on a not so interesting Maths lesson and making an origami from a rectangular a mm  ×  b mm sheet of paper (a > b). Usually the first step in making an origami is making a square piece of paper from the…

题目传送门 /* 水题 a或b成倍的减 */ #include <cstdio> #include <iostream> #include <algorithm> #include <cmath> #include <cstring> #include <string> #include <map> #include <set> #include <vector> #include <set&…

题目链接: http://codeforces.com/contest/676/problem/C 题解: 把连续的一段压缩成一个数,对新的数组求前缀和,用两个指针从左到右线性扫一遍. 一段值改变一部分的情况考虑的不够周到,wa了两次. #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<cmath> #include<vect…

C. Vasya and String 题目连接: http://www.codeforces.com/contest/676/problem/C Description High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and 'b' only. Vasya denotes beauty of the string as th…