8607: GRL_4_A : Cycle Detection for a Directed Graph
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Description
Find a cycle in a directed graph G(V,E).
Input
In the first line, two integers |V| is the number of vertices and |E| is the number of edges in the graph. The graph vertices are named with the numbers 0, 1,..., |V|-1 respectively.
In the following |E| lines, two integers $s_i$ and $t_i$ represent source and target verticess of i-th edge (directed).
Output
Print 1 if G has cycle(s), 0 otherwise.
Constraints
$1 ≤ |V| ≤ 100$
$0 ≤ |E| ≤ 1,000$
$s_i ≠ t_i$
$0 ≤ |E| ≤ 1,000$
$s_i ≠ t_i$
Sample 1 Input
3 3
0 1
0 2
1 2
Sample 1 Output
0
Sample 2 Input
3 3
0 1
1 2
2 0
Sample 2 Output
1