Compilare: main.cpp: In function 'int main()': main.cpp:33:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 33 | for(int i = 0; i<s.length(); i++) | ~^~~~~~~~~~~ main.cpp:51:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 51 | for(int i = 2; i<=s.length(); i++) | ~^~~~~~~~~~~~ main.cpp:64:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 64 | for(int i = 2; i<=(s.length()-k); i++) | ~^~~~~~~~~~~~~~~~