Compilare: main.cpp: In function 'void solve_2()': main.cpp:18:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | for (int i=0;i<p.size();i++) { | ~^~~~~~~~~ main.cpp:30:32: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | if (st>=0 && dr<p.size() && p[st].first==p[dr].first) { | ~~^~~~~~~~~ main.cpp:29:21: warning: unused variable 'secvsize' [-Wunused-variable] 29 | int secvsize = 0; | ^~~~~~~~