Compilare: user.cpp: In function ‘void DFS(int)’: user.cpp:51:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<v[nod].size();k++) ^ user.cpp: In function ‘int main()’: user.cpp:103:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(q=0;q<v[ans[0]].size() && ok1;q++) ^ user.cpp:113:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<b.size();i++) ^ user.cpp:59:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.in","r",stdin); ^ user.cpp:60:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("johnie.out","w",stdout); ^ user.cpp:61:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&m); ^ user.cpp:64:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&x,&y); ^