B. The Time 题目连接: http://www.codeforces.com/contest/622/problem/B Description You are given the current time in 24-hour format hh:mm. Find and print the time after a minutes. Note that you should find only the time after a minutes, see the examples t…
A. Infinite Sequence 题目连接: http://www.codeforces.com/contest/622/problem/A Description Consider the infinite sequence of integers: 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5.... The sequence is built in the following way: at first the number 1 is wr…
A. Divisibility Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/597/problem/A Description Find the number of k-divisible numbers on the segment [a, b]. In other words you need to find the number of such integer values x tha…
A. Towers 题目连接: http://www.codeforces.com/contest/37/problem/A Description Little Vasya has received a young builder's kit. The kit consists of several wooden bars, the lengths of all of them are known. The bars can be put one on the top of the other…
https://codeforc.es/contest/1194/problem/B 好像也没什么思维,就是一个水题,不过蛮有趣的.意思是找缺黑色最少的行列十字.用O(n)的空间预处理掉一维,然后用O(n)的时间根据另一维计算出答案. #include<bits/stdc++.h> using namespace std; typedef long long ll; int n, m; string g[50005]; int rq[50005]; int main() { #ifdef Yi…
题目 //行开始看被吓一跳,那么大,没有头绪, //看了解题报告,发现这是一道大大大的水题,,,,,//2009 = 7 * 7 * 41//对2009分解,看它有哪些质因子,它最大的质因子是41,那么对于大于等于41的数,直接输出0就行了. #include<stdio.h> #include<string.h> #include<algorithm> using namespace std; int main() { int n; while(scanf("…
题目链接: A. Vanya and Fence time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Vanya and his friends are walking along the fence of height h and they do not want the guard to notice them. In orde…
题意:给定 n 条边,判断是不是树. 析:水题,判断是不是树,首先是有没有环,这个可以用并查集来判断,然后就是边数等于顶点数减1. 代码如下: #include <bits/stdc++.h> using namespace std; const int maxn =1000 + 5; int p[maxn]; int Find(int x){ return x == p[x] ? x : p[x] = Find(p[x]); } int main(){ int n, m, x, y; cin…
Codeforces 1082B Vova and Trophies https://vjudge.net/problem/CodeForces-1082B 题目: Vova has won nn trophies in different competitions. Each trophy is either golden or silver. The trophies are arranged in a row. The beauty of the arrangement is the le…
题意:你要从A到B去上班,然而这中间有n条河,距离为d.给定这n条河离A的距离p,长度L,和船的移动速度v,求从A到B的时间的数学期望. 并且假设出门前每条船的位置是随机的,如果不是在端点,方向也是不定的,你在陆地行走速度为1,输入保证河在AB之前,并且不会重叠. 析:一看这个题,好像不会啊...这怎么求,这么乱,这么复杂... 但是仔细一想求时间期望,不就是在过河的地方时间不是固定的么,只要求出过河的时间的数学期望,利用数学期望的线性,加起来就OK了. 这样一想感觉就不乱了,那么怎么求每个河的…