Kruskal

ll root (ll x) {
    while (id[x] != x)
        x = id[x];
    return x;
}

ll Union (ll x, ll y) {
    ll p = root(x), q = root(y);
    if (p != q) {
        if (sz[p] < sz[q])
            swap(p, q);
        id[q] = p;
        sz[p] += sz[q];
    }
}

ll Kruskal () {
    ll shit = 0;
    for (ll i = 0; i < edges.size(); i++) {
        ll cost = edges[i].F;
        ll u = edges[i].S.F;
        ll v = edges[i].S.S;
        if (root(u) != root(v)) {
            Union(u, v);
            shit += cost;
        }
    }
    return shit;
}