Compilare: main.cpp: In function 'int main()': main.cpp:31:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<A.size(); i++) ~^~~~~~~~~ main.cpp:35:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<A.size()&&A[i].first<=A[j].first&&A[j].second<=A[i].second) ~^~~~~~~~~