hdu3938 Portal

Problem Description

ZLGG found a magic theory that the bigger banana the bigger banana peel .This important theory can help him make a portal in our universal. Unfortunately, making a pair of portals will cost min{T} energies. T in a path between point V and point U is the length of the longest edge in the path. There may be lots of paths between two points. Now ZLGG owned L energies and he want to know how many kind of path he could make.

 

Input

There are multiple test cases. The first line of input contains three integer N, M and Q (1 < N ≤ 10,000, 0 < M ≤ 50,000, 0 < Q ≤ 10,000). N is the number of points, M is the number of edges and Q is the number of queries. Each of the next M lines contains three integers a, b, and c (1 ≤ a, b ≤ N, 0 ≤ c ≤ 10^8) describing an edge connecting the point a and b with cost c. Each of the following Q lines contain a single integer L (0 ≤ L ≤ 10^8).

 

Output

Output the answer to each query on a separate line.

 

Sample Input

10 10 10 7 2 1 6 8 3 4 5 8 5 8 2 2 8 9 6 4 5 2 1 5 8 10 5 7 3 7 7 8 8 10 6 1 5 9 1 8 2 7 6

 

Sample Output

36 13 1 13 36 1 36 2 16

13

题目要求a、b两点之间所有的路径中的最大边的最小值。

这题可以用并查集做，因为询问次数很多，所以要离线操作。设数组num[i],只记录i所在集合的总顶点数（一开始以为是记录边的，其实是记录顶点的），先对所有的边排序，从小到大，（其实可以看做是依次枚举最大边的最小值，因为如果这条线段的两端点不在一个集合，即两个集合的边不相连，那么这条线段就起到了桥梁的作用，也就是说任意两个集合的点相连都要通过这条边，因为之前两个集合的最大边的最小值都符合条件，那么如果这条线段也符合条件，就可以把两个集合的点都连起来），因为能量大的值一定包括能量小的路径，所以每次初始化的时候p[i].sum=p[i-1].sum;

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转载于:https://www.cnblogs.com/herumw/p/9464801.html