Compilare: user.cpp: In function ‘void go_visit(int)’: user.cpp:12:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod[pos].size();i++) ~^~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:47:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ans.size();i++) ~^~~~~~~~~~~ user.cpp:49:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<component[ans[i]].size();j++) ~^~~~~~~~~~~~~~~~~~~~~~~~~ user.cpp:25:32: 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:26:34: 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:27:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&n,&m); ^ user.cpp:30:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n",&x,&y); ^