Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:28:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < arr[node].size(); i++) { ^ user.cpp: In function ‘int main()’: user.cpp:39:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.in", "r", stdin); ^ user.cpp:40:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bfs.out", "w", stdout); ^