#define HAVE_STRUCT_TIMESPEC#include<bits/stdc++.h>using namespace std;char s[100007];int main(){ cin>>s+1; int n=strlen(s+1); int cnt=0; for(int i=n;i>=1;--i){//从后向前,保证后面的解都是合法的情况下 if(s[i]=='1'){//如果当前位置的数字是1 if(cnt)//i后面1的个数小于0的个数,此时如果把i位…

Codeforces Round #581 (Div. 2)-E. Natasha, Sasha and the Prefix Sums-动态规划+组合数学 [Problem Description] ​ 给你\(n\)个\(1\),\(m\)个\(-1\),他们任意排列有\(\frac{(n+m)!}{n!\cdot m!}\)中排列,每种排列都有一个最大前缀和(可能为\(0\)),求所有排列的最大前缀和之和为多少. [Solution] ​ 定义\(dp[i][j]\)表示有\(i\)个\(…

A. Two Substrings 题意:给一个字符串,求是否含有不重叠的子串"AB"和"BA",长度1e5. 题解:看起来很简单,但是一直错,各种考虑不周全,最后只能很蠢的暴力,把所有的AB和BA的位置求出来,能有一对AB和BA不重叠即可. #include <bits/stdc++.h> using namespace std; ]; vector<int> ab; vector<int> ba; int main() { w…

题意:https://codeforc.es/problemset/problem/1204/D2 给你一个01串,如:0111001100111011101000,让你改这个串(使0尽可能多,任意 l~r 的LIS最长上升子序列长度不变). 问:0111001100111011101000 答:0011001100001011101000 思路: 参考题解:考虑什么串无法该变. 1. 10无法被改变(我们称为固定串),00,01,11都可以改. 2. 固定串+固定串(无法被改变). 3. 1+…

D2. Kirk and a Binary String (hard version) time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output The only difference between easy and hard versions is the length of the string. You can hack this pro…

A. BowWow and the Timetable time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output In the city of Saint Petersburg, a day lasts for 2100 minutes. From the main station of Saint Petersburg, a train dep…

题目连链接:http://codeforces.com/contest/231 A. Team time limit per test:2 seconds memory limit per test:256 megabytes One day three best friends Petya, Vasya and Tonya decided to form a team and take part in programming contests. Participants are usually…

C https://codeforces.com/contest/1130/problem/C 题意 给你一个\(n*m\)(n,m<=50)的矩阵,每个格子代表海或者陆地,给出在陆地上的起点终点,只允许挖一条穿越海的隧道,假设隧道连接的两个陆地分别为(x1,y1),(x2,y2),则挖隧道的花费为\((y1-x1)*(y1-x1)+(y2-x2)*(y2-x2)\) 题解 分别找出和起点,和终点连接的陆地(找联通块),枚举两个点维护最小值 代码 #include<bits/stdc++.h&…

C. Necklace 题目连接: http://www.codeforces.com/contest/613/problem/C Description Ivan wants to make a necklace as a present to his beloved girl. A necklace is a cyclic sequence of beads of different colors. Ivan says that necklace is beautiful relative…

https://codeforces.com/contest/1256 A:Payment Without Change[思维] 题意:给你a个价值n的物品和b个价值1的物品,问是否存在取物方案使得价值为s 题解:min(s/n,a)*n+b>=s?YES:NO #include<iostream> #include<cstdio> #include<cstdlib> #include<cmath> #include<algorithm>…