Problems
Depth first search on a disconnected graph
Depth first search on a disconnected graph
Undirected disconnected graph is given. Run depth first search on it. For each vertex print the timestamps when it becomes gray / black in the order of their first visit.
Input
First line contains number of vertices n (n ≤ 100) of undirected graph. Each next line contains two vertices a and b - an undirected edge of the graph.
Output
Run depth first search on a graph. For each vertex print the timestamps when it becomes gray / black in the order of their first visit.
Input example #1
6 1 2 5 6 2 4 1 4
Output example #1
Vertex: 1, Gray 1, Black 6 Vertex: 2, Gray 2, Black 5 Vertex: 4, Gray 3, Black 4 Vertex: 3, Gray 7, Black 8 Vertex: 5, Gray 9, Black 12 Vertex: 6, Gray 10, Black 11