# 「POJ1741」Tree

2014年6月15日8,00414

Description

Give a tree with n vertices,each edge has a length(positive integer less than 1001).
Define dist(u,v)=The min distance between node u and v.
Give an integer k,for every pair (u,v) of vertices is called valid if and only if dist(u,v) not exceed k.
Write a program that will count how many pairs which are valid for a given tree.

Input

The input contains several test cases. The first line of each test case contains two integers n, k. (n<=10000) The following n-1 lines each contains three integers u,v,l, which means there is an edge between node u and v of length l.
The last test case is followed by two zeros.

Output

For each test case output the answer on a single line.

Sample Input

Sample Output

$$ans1-\sum ans2$$即为最后的ans

1.点分治+排序

2.点分治+treap

### 说点什么

WAL

int main（） 里面不是可以直接work（root）

zzh

y20070316

De℃,.: )

cjk_steps