loops
Problem
Given the adjacency matrix of an undirected graph, determine if it contains loops.
Input:
- the first line contains the number n (\(1<=n<=100\)) – number of graph vertices;
- then the adjacency matrix is set - n rows of n numbers, each of which is equal to 0 or 1 .
Output: output "YES" if the graph contains loops, and "NO" otherwise.
Examples
| # |
Input |
Output |
| 1 |
5
1 1 1 1 0
1 0 1 1 1
1 1 0 1 1
1 1 1 1 1
0 1 1 1 0
|
YES |