Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:14:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v[nod].size();i++) ^ user.cpp: In function ‘void dfs1(int)’: user.cpp:23:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vt[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:50:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<r[i].size();j++) ^ user.cpp:29:32: 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:30:34: 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:32:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:35:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^