题目大概说给一个由a和b组成的字符串,最多能改变其中的k个字符,问通过改变能得到的最长连续且相同的字符串是多长. 用尺取法,改变成a和改变成b分别做一次:双指针i和j,j不停++,然后如果遇到需要改变且改变次数用完就让i++更正改变次数,最后更新答案.时间复杂度O(n). 另外,注意到k=0的情况. #include<cstdio> #include<cstring> #include<algorithm> using namespace std; ]; int mai…

题目连接:http://codeforces.com/contest/676/problem/C 题意:一串字符串,最多改变k次,求最大的相同子串 题解:很明显直接尺取法 #include<cstdio> #include<cstring> #include<cmath> #include<string> #include<set> #include<map> #include<vector> #include<qu…

简单的尺取法…… 先找到右边界 然后在已经有了所有字母后减小左边界…… 不断优化最短区间就好了~ #include<stdio.h> #include<string.h> #define M(a,b) memset(a,b,sizeof(a)) ]; ]; ]; ]; int sum; int main(){ int n; while(~scanf("%d",&n)){ getchar(); M(zimu,); M(in,false); gets(a);…

String Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 65536/65536 K (Java/Others) Problem Description There is a string S.S only contain lower case English character.(10≤length(S)≤1,000,000)How many substrings there are that contain at least…

C. They Are Everywhere time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Sergei B., the young coach of Pokemons, has found the big house which consists of n flats ordered in a row from left…

String Problem Description There is a string S.S only contain lower case English character.(10≤length(S)≤1,000,000)How many substrings there are that contain at least k(1≤k≤26) distinct characters?   Input There are multiple test cases. The first lin…

题目链接: C. Foe Pairs time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output   You are given a permutation p of length n. Also you are given m foe pairs (ai, bi) (1 ≤ ai, bi ≤ n, ai ≠ bi). Your task…

题目大概说给一个由01组成的序列,要求最多把k个0改成1使得连续的1的个数最多,输出一种方案. 和CF 676C相似. #include<cstdio> #include<algorithm> using namespace std; ]; int main(){ int n,k; scanf("%d%d",&n,&k); ; i<n; ++i){ scanf("%d",a+i); } ){ ,cnt=;; ; i<…

题目大概说手机有n张照片.通过左滑或者右滑循环切换照片,滑动需要花费a时间:看一张照片要1时间,而看过的可以马上跳过不用花时间,没看过的不能跳过:有些照片要横着看,要花b时间旋转方向.那么问T时间下最多可以看多少张相片. 先确定左滑最多能看到哪张,然后用另一个指针从第一张照片往右移动,这代表先右滑然后左滑的方式看照片,而每次向右的指针移动计算其时间,不合法的话就通过向左的指针向右移修正时间: 而先左滑然后右滑的方式同理. 模拟题,好难写..不过写好后提交居然就1A了.. #include<cst…

题目链接: C. Vasya and String time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output High school student Vasya got a string of length n as a birthday present. This string consists of letters 'a' and '…