Compilare: user.cpp: In function ‘void bfs(int)’: user.cpp:21:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[u].size();i++) ^ user.cpp:28:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int r=0;r<G[v].size();r++) ^ user.cpp: In function ‘int main()’: user.cpp:45:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.in","r",stdin); ^ user.cpp:46:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ciclueuler.out","w",stdout); ^ user.cpp:47:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:50:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^