poj1258 prim算法

#include<cstdio>
#include<cstring>
#define INF 0x3f3f3f3f
using namespace std;
//prim算法，没有很难，再看看就好了
int matrix[105][105];
int dis[105];
bool vis[105];
int n;
void prim()
{
    memset(vis,0,sizeof(vis));
    int ans = 0,Min,tmp;
    vis[0] = 1;
    for(int i = 0; i<n; ++i)
        dis[i] = matrix[0][i];
    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;
        //重点，加完点要更新所有点的距离
        for(int i = 0; i<n; ++i)
        {
            if(!vis[i]&&dis[i]>matrix[tmp][i])
                dis[i] = matrix[tmp][i];
        }
    }
    for(int i = 0; i<n; ++i)
        ans += dis[i];
    printf("%d\n",ans);
}
int main()
{
    while(~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;
}