Compilare: main.cpp: In function 'int main()': main.cpp:28:23: 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 k = 2; k <= s.length () / 3; k++) | ~~^~~~~~~~~~~~~~~~~~ main.cpp:30:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | for(int i = 0; i <= s.length () - 3 * k; i++) | ~~^~~~~~~~~~~~~~~~~~~~~~ main.cpp:32:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 32 | for (int j = i + k; j <= s.length () - 2 * k; j++) | ~~^~~~~~~~~~~~~~~~~~~~~~ main.cpp:37:43: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 37 | for (int t = j + k; t <= s.length () - k; t++) | ~~^~~~~~~~~~~~~~~~~~