poj1287 16ms prim

#include<cstdio>
#include<cstring>
#include<algorithm>
#define INF 0x3f3f3f3f
using namespace std;
int matrix[105][105];
bool vis[105];
int dis[105];
int n,r,ans,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 j = 0; j<n; ++j)
        {
            if(!vis[j]&&dis[j]>matrix[tmp][j])
                dis[j] = matrix[tmp][j];
        }
    }
    for(int i = 0; i<n; ++i)
        ans += dis[i];
    printf("%d\n",ans);
}
int main()
{
    int v1,v2,val;
    while(scanf("%d",&n),n)
    {
        scanf("%d",&r);
        ans = 0;
        memset(vis,0,sizeof(vis));
        for(int i = 0; i<n; ++i)
            for(int j = 0; j<n; ++j)
                matrix[i][j] = (i==j)?0:INF;
        while(r--)
        {
            scanf("%d%d%d",&v1,&v2,&val);
            matrix[v1-1][v2-1] = matrix[v2-1][v1-1] = min(val,min(matrix[v1-1][v2-1],matrix[v2-1][v1-1]));
        }
        prim();
    }
    return 0;
}