Compilare: main.cpp: In function 'void back()': main.cpp:36:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 36 | for(int i = 0; i < sol.size(); i++){ | ~~^~~~~~~~~~~~ main.cpp:46:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 46 | for(int i = 0; i < sol.size(); i++){ | ~~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:86:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 86 | for(int i = 0; i < final_moves.size(); i++){ | ~~^~~~~~~~~~~~~~~~~~~~