Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:17:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nod].size();++i) ^ user.cpp: In function ‘void DFS1(int)’: user.cpp:27:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v1[nod].size(); ++i) ^ user.cpp: In function ‘int main()’: user.cpp:60:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<C[i].size();++j) printf("%d ",C[i][j]); ^ user.cpp:34:32: 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:35:34: 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",&x,&y); ^