#5637. Fixed Length Walk Queries
Fixed Length Walk Queries
Fixed Length Walk Queries
You are given an undirected graph with n nodes and m edges. The graph is simple and connected. You start at a specific node, and on each turn you must move through an edge to another node. Your task is to answer q queries of the form: "is it possible to start at node a and end up on node b after exactly x turns?"
Input
The first line contains three integers n, m and q: the number of nodes, edges and queries. The nodes are numbered 1,2,\dots,n. After this, there are m lines which describe the edges. Each line contains two integers a and b: there is an edge between nodes a and b. Finally, there are q lines, each describing a query. Each line contains three integers a, b and x.
Output
For each query, print the answer (YES or NO) on its own line.
Constraints
Example
Input
4 5 6
1 2
2 3
1 3
2 4
3 4
1 2 2
1 4 1
1 4 5
2 2 1
2 2 2
3 4 8
Output
YES
NO
YES
NO
YES
YES
Explanation:
In query 1, a possible route is 1 \rightarrow 3 \rightarrow 2.
In query 3, a possible route is 1 \rightarrow 3 \rightarrow 2 \rightarrow 1 \rightarrow 3 \rightarrow 4.
In query 6, a possible route is 3 \rightarrow 4 \rightarrow 2 \rightarrow 3 \rightarrow 4 \rightarrow 2 \rightarrow 1 \rightarrow 3 \rightarrow 4.