Problem number 03

#include<stdio.h>
int main()
{
    int n,i,j,m,r;
    printf("[?]*[?] = \n");
    scanf("%d%d",&m,&n);
    int mat[m][n];
    for (i=0;i<m;i++)
    {
        for (j=0;j<n;j++)
        {
            mat[i][j]=0;
        }
    }
    int num;
    printf("Number of edges = \n");
    scanf("%d",&num);
    printf("Enter edges = \n");
    for (i=0;i<num;i++){
        int u,v;
        scanf("%d %d",&u,&v);
        mat[u][v]++;
        mat[v][u]++;
    }
    for (i=0;i<m;i++)
    {
        for(r=0;r<m;r++)
        {printf("---|");}
        printf("\n");
        for(j=0;j<n;j++)
        {
            printf(" %d |",mat[i][j]);
        }
        printf("\n");
    }
     for(r=0;r<m;r++)
        {printf("---|");}
        printf("\n");
    return 0;
}