3988. Transitivity of a graph

#include <stdio.h>
#include <stdlib.h>

const int N = 101;

bool gr[N][N];

int main()
{
    int n,m;
    scanf("%d %d",&n,&m);

    int a,b;

    for(int i = 0; i < m; ++i)
    {
        scanf("%d %d",&a,&b);
        gr[a][b] = 1;
        gr[b][a] = 1;
    }

    for(int i = 1; i <= n; ++i)
    {
        for(int j = i + 1; j <= n; ++j)
        {
            for(int k = j + 1; k <= n; ++k)
            {
                if((gr[i][j] && gr[j][k] && !gr[i][k])
                 ||(!gr[i][j] && gr[j][k] && gr[i][k])
                 ||(gr[i][j] && !gr[j][k] && gr[i][k]))
                {
                    printf("NO");
                    return 0;
                }
            }
        }
    }

    printf("YES");

    return 0;
}