Compilare: user.cpp: In function ‘int main()’: user.cpp:62:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=k;i++) ^ user.cpp:74:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<v.size();j++) ^ user.cpp:79:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<v.size() && v[j].first==tmp) ^ user.cpp:85:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<v.size() && v[j].second) ^ user.cpp:93:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=k;i++) ^ user.cpp:47:9: warning: unused variable ‘n’ [-Wunused-variable] ULL n=next_number(); ^