Compilare: user.cpp: In function ‘void bfs()’: user.cpp:14:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for ( i = 0 ; i < v[nod].size() ; ++ i ) { ^ user.cpp: In function ‘int main()’: user.cpp:28:37: 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:29:39: 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 ); ^ user.cpp:31:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d%d", &n, &m, &s ); ^ user.cpp:33:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf ( "%d%d", &x, &y ); ^