Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:17:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<G[nod].size();i++) ^ user.cpp: In function ‘void iDFS(int)’: user.cpp:26:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<iG[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:57:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(a=0;a<C[i].size();a++) ^ user.cpp:33:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.in","r",stdin); ^ user.cpp:34:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("ctc.out","w",stdout); ^ user.cpp:36:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:39:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&a,&b); ^