qaq,现在内心真是各种草泥马.怪自己见识短浅...哎... 题意: 给你一幅图,然后求一个最小花费使得所有的点都连通(这就是最小生成树啊),然后在这棵树上[如果我要从任意起点到任意终点,这两个点不同,且这两个点的被选取概率都是一样,求一个最小的期望长度,我的神队友的解释就是树上所有任意不同点之间的边值都加起来然后除以边的数量] 思路: ①:最小生成树: ②:求一个所有边之和/边的数量,一个边的贡献,对总和的贡献,就是任意两点之和,这个边被加了多少次,那就用这个边把树分成两部分,一部分有a个点,…

2016 Al-Baath University Training Camp Contest-1 A题:http://codeforces.com/gym/101028/problem/A 题意:比赛初始值是1500,变化了几次,得到的正确结果和bug后的是否相等.(Tourist大佬好 Y(^o^)Y) #include <bits/stdc++.h> using namespace std; int main() { int t; cin>>t; while(t--) { in…

Description ACM-SCPC-2017 is approaching every university is trying to do its best in order to be the Champion, there are n universities, the ith of them has exactly ai contestants. No one knows what is the official number of contestants in each team…

Description Tourist likes competitive programming and he has his own Codeforces account. He participated in lots of Codeforces Rounds, solved so many problems and became "Legendary Grand Master" (the highest rank on Codeforces). One day, he logg…

Description X is fighting beasts in the forest, in order to have a better chance to survive he's gonna buy upgrades for his weapon. Weapon upgrade shops are available along the forest, there are n shops, where the ith of them provides an upgrade with…

Description It is raining again! Youssef really forgot that there is a chance of rain in March, so he didn't fix the roof of his house. Youssef's roof is 1-D, and it contains n holes that make the water flow into the house, the position of hole i is…

 Description You've possibly heard about 'The Endless River'. However, if not, we are introducing it to you. The Endless River is a river in Cambridge on which David and Roger used to sail. This river has the shape of a circular ring, so if you kept…

Description The forces of evil are about to disappear since our hero is now on top on the tower of evil, and all what is left is the most evil, most dangerous monster! The tower has h floors (numbered from 1 to h, bottom to top), each floor has w roo…

Description Zaid has two words, a of length between 4 and 1000 and b of length 4 exactly. The word a is 'good' if it has a substring which is equal tob. However, a is 'almost good' if by inserting a single letter inside of it, it would become 'good'.…

Description X is well known artist, no one knows the secrete behind the beautiful paintings of X except his friend Y, well the reason that Y knows X's secrete is that he is that secret. Y is a programmer and he helps X with drawing paintings using co…