BOJ 4013 ATM

void solve(){
    cin >> N >> M;
    DirectedGraph graph(N+1);
    rep(i, 0, M){
        int u, v; cin >> u >> v;
        graph.add_edge(u, v);
    }
    DirectedGraph dag = graph.getCompressedGraph();
    int sz = dag.V;
    vector<int> val(sz), DP(sz, -1e9), indeg(sz, 0);
    rep(i, 1, N+1){
        int X; cin >> X;
        val[graph.sccId[i]] += X;
    }
    int S, P; cin >> S >> P;
    S = graph.sccId[S];
    DP[S] = val[S];
    rep(u, 0, sz) for(auto &v: dag.links[u]) indeg[v]++;
    queue<int> Q;
    rep(i, 0, sz) if(indeg[i] == 0) Q.push(i);
    while(!Q.empty()){
        int cur = Q.front(); Q.pop();
        for(auto nxt: dag.links[cur]){
            DP[nxt] = max(DP[nxt], DP[cur] + val[nxt]);
            indeg[nxt]--;
            if(indeg[nxt] == 0) Q.push(nxt);
        }
    }
    int ans = 0;
    rep(i, 0, P){
        int X; cin >> X;
        X = graph.sccId[X];
        ans = max(ans, DP[X]);
    }
    cout << ans << '\n';
}