Compilare: user.cpp: In function ‘int main()’: user.cpp:13:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (fr[i].size()>maxx) { maxx=fr[i].size(); pas=i; } ^ user.cpp:15:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<fr[pas].size();i++) printf("%d\n",fr[pas][i]); ^ user.cpp:8:15: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:10:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); fr[x].push_back(i); ^