题目:http://codeforces.com/problemset/problem/437/D 题意:有n个点,m条边的无向图,保证所有点都能互通,n,m<=10^5 每个点都有权值,每条边的权值定义为这条边连接两点的权值中的最小值. f(p,q)表示p到q的路径中边权的最小值,如果有多条路经,就取每条路径最小值中的最小值 要求的就是对于所有1<=p<=n,1<=q<=n,p≠q,f(p,q)的平均值 分析: 刚开始是想考虑每条边对总和的贡献,结果没想通. 一个很巧的办法…
B. The Child and Zoo Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/438/problem/B Description Of course our child likes walking in a zoo. The zoo has n areas, that are numbered from 1 to n. The i-th area contains ai animal…
D. The Child and Zoo time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Of course our child likes walking in a zoo. The zoo has n areas, that are numbered from 1 to n. The i-th area contains …
题目链接:D. The Child and Zoo 题意: 题意比较难懂,是指给出n个点并给出这些点的权值,再给出m条边.每条边的权值为该条路连接的两个区中权值较小的一个.如果两个区没有直接连接,那么f值即为从一个区走到另一个区中所经过的路中权值最小的值做为权值.如果有多条路的话,要取最大的值作为路径的长度.问,平均两个区之间移动的权值为多少. 题解: 每条边的长度已经知道了,因为路径的权值取这条路中最小的且多条路的话则取较大的,那么我们其实可以从比较大的边开始取(先把边排序),用并查集开始合并…
D. Dividing Kingdom II 题目连接: http://www.codeforces.com/contest/687/problem/D Description Long time ago, there was a great kingdom and it was being ruled by The Great Arya and Pari The Great. These two had some problems about the numbers they like, so…
题目地址:24道CF的DIv2 CD题有兴趣可以做一下. ACM思维题训练集合 Bajtek is learning to skate on ice. He's a beginner, so his only mode of transportation is pushing off from a snow drift to the north, east, south or west and sliding until he lands in another snow drift. He ha…
D. The Child and Sequence Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/438/problem/D Description At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of important…
A. The Child and Toy Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/438/problem/A Description On Children's Day, the child got a toy from Delayyy as a present. However, the child is so naughty that he can't wait to destroy…
     好题啊,被HACK了.曾经做题都是人数越来越多.这次比赛 PASS人数 从2000直掉 1000人  被HACK  1000多人! ! ! ! 没见过的科技啊 1 2 4 8 这组数 被黑的 A. The Child and Homework time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Once upon a ti…
D. The Child and Sequence time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of…