Compilare: main.cpp: In function 'int main()': main.cpp:84:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 84 | while( i < s.size() ){ | ~~^~~~~~~~~~ main.cpp:89:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 89 | while( i < s.size() && isdigit(s[i]) ){ | ~~^~~~~~~~~~ main.cpp:105:18: warning: unused variable 'ch' [-Wunused-variable] 105 | char ch = s[i]; | ^~