View Code of Problem 131

#include<iostream>
#include<cmath>
#include<iomanip>
#include<cstring>
using namespace std;
int map[101][101];
int main()
{
	
	int n, m;
	while (cin >> n >> m)
	{
		memset(map, 0, sizeof(map));
		while (m--)
		{
			int a, b;
			cin >> a >> b;
			map[a][b] = 1;
		}
		for (int i = 1;i <= n;i++)
		{
			for (int j = 1;j <= n;j++)
			{
				for (int k = 1;k <= n;k++)
				{
					if (map[j][i] && map[i][k])
					{
						map[j][k] = 1;
					}
				}
			}
		}
		int flag = 0;
		for (int i = 1;i <= n;i++)
		{
			for (int j = 1;j <= n;j++)
			{
				if (i != j)
				{
					if (map[i][j] && map[j][i])
					{
						flag = 1;
						break;
					}
				}
			}
		}
		if (flag == 1)
			cout << "ERROR" << endl;
		else
			cout << "RIGHT" << endl;
	}
	
	
}