- Time limit: 1.00 s
- Memory limit: 512 MB
Given a tree of n nodes, your task is to count the number of distinct paths that have at least k_1 and at most k_2 edges.
The first input line contains three integers n, k_1 and k_2: the number of nodes and the path lengths. The nodes are numbered 1,2,\ldots,n.
Then there are n-1 lines describing the edges. Each line contains two integers a and b: there is an edge between nodes a and b.
Print one integer: the number of paths.
- 1 \le k_1 \le k_2 \le n \le 2 \cdot 10^5
- 1 \le a,b \le n
5 2 3 1 2 2 3 3 4 3 5