Compilare: user.cpp: In function ‘int bfs()’: user.cpp:23:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v[nod].size (); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:40:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("reinvent.in", "r", stdin); ^ user.cpp:41:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("reinvent.out", "w", stdout); ^ user.cpp:44:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d%d", &n, &m, &k); ^ user.cpp:47:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d%d", &x, &y); ^ user.cpp:56:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &x); ^