Compilare: user.cpp: In function ‘int main()’: user.cpp:2:298: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] std::ifstream f("costuri.in");std::ofstream g("costuri.out");typedef std::vector<int>v;std::map<int,v>M;int n,q,p,c,x,z;int main(){f>>n;for(int i=1;i<=n;i++){z=1;f>>x;q=x;if(x==0)M[0].push_back(x);else{while(x){z*=x%10;x/=10;}M[z].push_back(q);}}f>>q;for(int i=1;i<=q;i++){f>>p>>c;if(M[c].size()>=p)g<<M[c][p-1]<<"\n";else g<<-1<<"\n";}} ^