1140. 最短网络

(prim)模板题，起点可选任意一个点。

const int N = 110;
int g[N][N];
int dist[N];
bool vis[N];
int n;

int prim() {
    memset(dist, 0x3f, sizeof dist);
    dist[0] = 0;

    int res = 0;
    for(int i = 0; i < n; i++) {
        int t = -1;
        for(int j = 0; j < n; j++)
            if(!vis[j] && (t == -1 || dist[t] > dist[j]))
                t = j;

        vis[t] = true;
        res += dist[t];

        for(int j = 0; j < n; j++)
            dist[j] = min(dist[j], g[t][j]);
    }
    return res;
}

int main() {
    cin >> n;

    for(int i = 0; i < n; i++)
        for(int j = 0; j < n; j++)
            cin >> g[i][j];

    int t = prim();
    cout << t << endl;
    //system("pause");
    return 0;
}