Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:10:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<V1[nod].size();i++) ^ user.cpp: In function ‘void DFSt(int)’: user.cpp:19:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<V2[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:45:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] {for(j=0;j<VS[i].size();j++) ^ user.cpp:25:29: 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:26:31: 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:27:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:29:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] {scanf("%d%d",&x,&y); ^