Compilare: main.cpp: In function 'void add(std::string)': main.cpp:18:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 18 | for(int i = 0; i < str.size(); i++){ | ~~^~~~~~~~~~~~ main.cpp: In function 'void prune(std::string)': main.cpp:44:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 44 | for(int i = 0; i < str.size(); i++){ | ~~^~~~~~~~~~~~ main.cpp: In function 'int get_cnt(std::string)': main.cpp:67:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 67 | for(int i = 0; i < str.size(); i++){ | ~~^~~~~~~~~~~~ main.cpp: In function 'int lp(std::string)': main.cpp:81:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 81 | for(int i = 0; i < str.size(); i++){ | ~~^~~~~~~~~~~~