C. Anna, Svyatoslav and Maps time limit per test2 seconds memory limit per test256 megabytes inputstandard input outputstandard output The main characters have been omitted to be short. You are given a directed unweighted graph without loops with n v…

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:暴力. #include<cstdio> #include<cstring> #include<iostream> #include<algorithm> #define rep(i,l,r) for (int i=(l); i<=(r); i++) typedef long long ll; using namespace std;   ; int n; char s[N];   int main(){ scanf(); n=strlen(s+)…

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…

B. Mislove Has Lost an Array time limit per test1 second memory limit per test256 megabytes inputstandard input outputstandard output Mislove had an array a1, a2, ⋯, an of n positive integers, but he has lost it. He only remembers the following facts…

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…

#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…

B. Legacy 题目连接: http://codeforces.com/contest/786/problem/B Description Rick and his co-workers have made a new radioactive formula and a lot of bad guys are after them. So Rick wants to give his legacy to Morty before bad guys catch them. There are…

题目链接:http://codeforces.com/problemset/problem/1204/C 给定一组序列,P1,P2,P3...Pm,这是一组合法路径的序列,即任意的Pi和Pi+1之间有边相连,求一组新的序列V,V为原序列P的子集(通过删除P中某些元素获得), 且顺序遍历V序列中的各个顶点时,P序列这组路径是遍历所有V序列顶点的最短路径,输出V序列元素的个数和V序列各个元素. 思路:首先floyd计算各个顶点相互之间到达的最短路径dist[ i ] [ i+1 ](i到i+1的最短…