prim算法学习

#include <iostream>
#include <string.h>
#include <algorithm>
#include <stdio.h>
using namespace std;
#define INF 10000000
int N, E;
int sum;
int town[600][1000];
void prim(){
    int dis[1000], vis[1000], now = 0, Min;
    sum = 0;
    memset(vis, 0, sizeof(vis));
    for(int i = 0; i < N; i++)
        dis[i] = INF;
    vis[0] = 1, dis[0] = 0;
    for(int i = 0; i < N; i++){
        for(int j = 0; j < N; j++)
            if(!vis[j] && dis[j] > town[now][j])
                dis[j] = town[now][j];
        Min = INF;
        for(int j = 0; j < N; j++){
            if(!vis[j] && dis[j] < Min)
                Min = dis[now = j];
        }
        vis[now] = 1;
    }
    for(int i = 0; i < N; i++)
        sum += dis[i];
    printf("%d\n", sum);
    return ;
}
int main(){
    int T;
    cin >> T;
    while(T--){
        sum = 0;
        cin >> N >> E;
        for(int i = 0; i < N; i++)
            for(int j = 0; j < N; j++)
                town[i][j] = INF;
        int A, B, K;
        for(int i = 0; i < E; i++){
            cin >> A >> B >> K;
            town[A][B] = K;
            town[B][A] = K;
        }
        prim();
    }
    return 0;
}