Compilare: main.cpp: In function 'int main()': main.cpp:71:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 71 | while (k < s.length() && s[k] == ' ') | ~~^~~~~~~~~~~~ main.cpp:74:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 74 | while (k < s.length()) | ~~^~~~~~~~~~~~ main.cpp:78:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 78 | while (k < s.length() && s[k] != ' ' && s[k] != '\n') | ~~^~~~~~~~~~~~ main.cpp:83:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 83 | while (k < s.length() && (s[k] == ' ' || s[k] == '\n')) | ~~^~~~~~~~~~~~