- Time limit: 1.00 s
- Memory limit: 512 MB
A directed graph consists of n nodes and m edges. The edges are numbered 1,2,\dots,n.
Your task is to answer q queries of the form "can you reach node b from node a?"
The first input line has three integers n, m and q: the number of nodes, edges and queries.
Then there are m lines describing the edges. Each line has two distinct integers a and b: there is an edge from node a to node b.
Finally there are q lines describing the queries. Each line consists of two integers a and b: "can you reach node b from node a?"
Print the answer for each query: either "YES" or "NO".
- 1 \le n \le 5 \cdot 10^4
- 1 \le m,q \le 10^5
4 4 3 1 2 2 3 3 1 4 3 1 3 1 4 4 1
YES NO YES