Prim

ll Prim (int x) {
    //PII = pair<ll, ll>
    priority_queue <PII, vector<PII>, greater<PII> > Q;
    ll total = 0;
    PII p;
    Q.push({0, x});
    while (!Q.empty()) {
        p = Q.top();
        Q.pop();
        x = p.S;
        if (vis[x] == true) continue;
        total += p.first;
        vis[x] = true;
        for (ll i = 0; i < adj[x].size(); i++) {
            ll y = adj[x][i].S;
            if (vis[y] == false)
                Q.push(adj[x][i]);
        }
    }
    return total;
}