Compilare: main.cpp: In function 'void decode(std::string)': main.cpp:35:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for (int i = 0; i < s.size(); ++i) | ~~^~~~~~~~~~ main.cpp:39:40: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 39 | while (isdigit (s[i]) && i + 1 < s.size()) | ~~~~~~^~~~~~~~~~ main.cpp:48:44: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 48 | while (isdigit (s[i]) && i + 1 < s.size()) | ~~~~~~^~~~~~~~~~