Compilare: user.cpp: In function ‘int main()’: user.cpp:129:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pg < gr1.size () && gr1[pg].second <= i) { ^ user.cpp:134:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (pq < query1.size () && query1[pq].second.first == i) { ^