Compilare: main.cpp: In function 'int mystoi(std::string)': main.cpp:20:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 20 | for (int i = 0;i < x.size();i++) | ~~^~~~~~~~~~ main.cpp: In function 'std::string pal_par(std::string)': main.cpp:28:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 28 | for (int i = 0;i < x.size();i++) | ~~^~~~~~~~~~ main.cpp: In function 'std::string pal_impar(std::string)': main.cpp:38:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 38 | for (int i = 0;i < x.size();i++) | ~~^~~~~~~~~~