Compilare: main.cpp: In function 'int main()': main.cpp:27:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 27 | for (int i = 0; i < v.size();) { | ~~^~~~~~~~~~ main.cpp:33:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | while (j < v.size() && v[j].first == v[i].first) { | ~~^~~~~~~~~~ main.cpp:37:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | for (int k = 0; k < cur.size(); ++k) { | ~~^~~~~~~~~~~~