Compilare: user.cpp: In function ‘int main()’: user.cpp:52:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < nodes[u].size(); ++i) { ^ user.cpp:19:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("autobuz.in", "r", stdin); ^ user.cpp:20:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("autobuz.out", "w", stdout); ^ user.cpp:24:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^