poj2585 157ms

#include<cstdio>
#include<cstring>
#define INF 0x3f3f3f3f
using namespace std;
//MST，prim
//MST找最大权值
int matrix[505][505];
int dis[505];
bool vis[505];
int t,n,Min,tmp;
void prim()
{
    for(int i = 0; i<n; ++i)
        dis[i] = matrix[0][i];
    vis[0] = 1;
    for(int i = 1; i<n; ++i)
    {
        Min = INF;
        for(int j = 1; j<n; ++j)
        {
            if(!vis[j]&&Min>dis[j])
            {
                Min = dis[j];
                tmp = j;
            }
        }
        vis[tmp] = 1;
        for(int i = 0; i<n; ++i)
        {
            if(!vis[i]&&dis[i]>matrix[tmp][i])
                dis[i] = matrix[tmp][i];
        }
    }
    tmp = 0;
    for(int i = 0; i<n; ++i)
    {
        if(tmp<dis[i])
           tmp = dis[i];
    }
    printf("%d\n",tmp);
}
int main()
{
    scanf("%d",&t);
    while(t--)
    {
        memset(vis,0,sizeof(vis));
        scanf("%d",&n);
        for(int i = 0; i<n; ++i)
        {
            for(int j = 0; j<n; ++j)
                scanf("%d",&matrix[i][j]);
        }
        prim();
    }
    return 0;
}