Compilare: user.cpp: In function ‘int main()’: user.cpp:3:264: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] std::ifstream f("costuri.in");std::ofstream g("costuri.out");std::map<int, std::vector<int>>M;int n,q,p,c,x,z,i;int main(){f>>n;for(i=1;i<=n;i++){z=1;f>>x;q=x;if(!x)M[0].l(x);else{while(x){z*=x%10;x/=10;}M[z].l(q);}}f>>q;for(i=1;i<=q;i++){f>>p>>c;if(M[c].size()>=p)g<<M[c][p-1]<<"\n";else g<<-1<<"\n";}} ^