Topological Sort

toposort.cpp

bool vis[MAXN];
void topodfs(int cur, vector<int> &ans) {
    if (vis[cur])
        return;
    vis[cur] = true;
    for (auto i : adj[cur])
        topodfs(i, ans);
    ans.push_back(cur);
}
vector<int> toposort() {
    vector<int> ans;
    for (int i = 0; i < N; i++)
        topodfs(i, ans);
    reverse(ans.begin(), ans.end());
    return ans;
}