Compilare: main.cpp: In function 'void merge(std::vector<std::pair<int, int> >&, std::vector<std::pair<int, int> >, std::vector<std::pair<int, int> >)': main.cpp:33:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a.size();++i){ ~^~~~~~~~~ main.cpp:34:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(((j+1)<b.size())&&b[j+1].first<=a[i].second) j++; ~~~~~^~~~~~~~~ main.cpp:35:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if((j+1)==b.size()&&b[j].second<a[i].second) break; ~~~~~^~~~~~~~~~ main.cpp:40:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;i<a.size();++i) sol.push_back(a[i]); ~^~~~~~~~~ main.cpp:41:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;j<b.size();++j) sol.push_back(b[j]); ~^~~~~~~~~