message: Update the-time-when-the-network-becomes-idle.cpp
diff: @@ -16,7 +16,7 @@ public:
  while (!empty(q)) {
  vector<int> new_q;
  for (const auto& u : q) {
  - for (int v : adj[u]) {
  + for (const auto& v : adj[u]) {
  if (lookup[v]) {
  continue;
  }
  