杭电 1869 六度分离

http://acm.hdu.edu.cn/showproblem.php?pid=1869

　　好吧我承认这道题运用到了Floyd Warshall算法，求任意两点之间的最小路径问题！相识权值为1，不相识权值为INF。

#include <stdio.h>
#define MAXN 110
#define INF 100
int mat[MAXN][MAXN];

int main()
{
    int n , m, i, j, k;
    int max;
    while( scanf("%d%d", &n, &m)  != EOF)
    {
        //对存储矩阵mat初始化
        for( i = 0; i < n; i++ )
            for( j = 0; j < n; j++ )
                mat[i][j] = INF;
        //获取矩阵mat的值
        for( k = 0; k < m; k++ )
        {
            scanf("%d%d", &i, &j);
            mat[i][j] = mat[j][i] = 1;
        }
        /*for( i = 0; i < n; i++ )
        {
            for( j = 0; j < n; j++ )
                printf( "%d ",mat[i][j] );
            printf("
");
        }*/
        //printf( "

" );
        //floyd_warshall算法
        for( k = 0; k < n; k++ )
            for( i = 0; i < n; i++ )
                for( j = 0; j < n; j++ )
                    if( mat[i][j] > mat[i][k] + mat[k][j] )
                        mat[i][j] = (mat[i][k] + mat[k][j]);
        /*for( i = 0; i < n; i++ )
        {
            for( j = 0; j < n; j++ )
                printf( "%d ",mat[i][j] );
            printf("
");
        }*/
                        
        //遍历mat数组，以辨别最大距离是否大于7
        max = 0;
        for( i = 0; i < n; i++ )
            for( j = 0; j < n; j++ )
                if( max < mat[i][j] )
                    max = mat[i][j];
        if( max <= 7 )
            printf("Yes
");
        else
            printf("No
");


    }
    return 0;
}