Compilare: main.cpp: In function 'void back(int, long long int)': main.cpp:10:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 10 | if(k == p.size() && b % 2 == 1){ | ~~^~~~~~~~~~~ main.cpp:14:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 14 | if(k == p.size() && b % 2 == 0){ | ~~^~~~~~~~~~~ main.cpp:18:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | if(k == p.size()){ | ~~^~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:62:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 62 | for(int i = 0; i < sol.size(); i++) | ~~^~~~~~~~~~~~