Compilare: main.cpp: In function 'int main()': main.cpp:55:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 55 | for (int i = 0; i < sol.size(); ++i) | ~~^~~~~~~~~~~~