Dijkestra Function

void Dijkestra (int sourceNode) {
    priority_queue <pair <ll, int>, vector<pair <ll, int> >, greater<pair <ll, int> > > pq;

    for (int i = 1; i < j; i++)
        dist[i] = INF;
    dist[sourceNode] = 0;

    pq.push ({0, sourceNode});
    while (!pq.empty()) {
        pair <ll, int> v = pq.top();
        pq.pop ();

        if (v.F != dist[v.S])
            continue;

        for (auto edge: adj[v.S]) {
            int to = edge.F, len = edge.S;
            if (dist[v.S] + len < dist[to]) {
                dist[to] = dist[v.S] + len;
                //pa[to] = v.S;
                pq.push ({dist[to], to});
            }
        }
    }

    return;
}