Compilare: user.cpp: In function ‘int main()’: user.cpp:9:11: warning: variable ‘fin’ set but not used [-Wunused-but-set-variable] FILE *fin, *fout; ^~~ user.cpp:9:17: warning: variable ‘fout’ set but not used [-Wunused-but-set-variable] FILE *fin, *fout; ^~~~ user.cpp:12:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &V, &N); ^ user.cpp:14:56: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1; i<=N; i++) {scanf("%d", &numList[i].first); if(numList[i].first!=numList[i-1].first)vf++; numList[i].second=vf; groupList[vf]++; if(groupList[vf]>maxgroup)maxgroup=groupList[vf];} ^