Contest1263/C.cpp

#include <bits/stdc++.h>
using namespace std;
const int MAXN = 101;
int a[MAXN][MAXN];
int dis[MAXN];//每个点到源点的距离
int book[MAXN];//每个点是否加入到最小生成树中
int n;
int Prim(){
    for(int i = 1; i <= n; i++){
        dis[i] = INT_MAX;
    }
    for(int i = 1; i <= n; i++){
        book[i] = 0;
    }
    dis[1] = 0;
    book[1] = 1;
    for(int i = 1; i < n; i++){
        int u=1, MIN = INT_MAX;//寻找离最小生成树距离最短的点
        for(int j = 2; j <= n; j++){
            if(book[j] == 0 && dis[j] < MIN){
                MIN = dis[j];
                u = j;
            }
        }
        book[u] = 1;
        for(int j = 1; j <= n; j++){
            if(book[j] == 0 && dis[j] > a[u][j]){
                dis[j] = a[u][j];
            }
        }
    }
    int sum = accumulate(dis+1, dis+n+1,0);
    return sum;
}
int main(){
//    ifstream cin("input.txt");
//    ofstream cout("output.txt");
    while(cin >> n ){
        if(n == 0)break;
        for(int i = 1; i <= n; i++){
            for(int j = 1; j <= n; j++){
                a[i][j] = 0;
            }
        }
        for(int i = 1; i <= n * ( n - 1) / 2; i++){
            int x, y, z;
            cin >> x >> y >> z;
            a[x][y] = a[y][x] = z;
        }
        int sum = Prim();
        cout << sum << endl;
    }
}