Compilare: main.cpp: In function 'int main()': main.cpp:60:12: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 60 | while (i < s.size()) { | ~~^~~~~~~~~~ main.cpp:80:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 80 | if (x <= s.size() / 2) | ~~^~~~~~~~~~~~~~~ main.cpp:96:12: warning: unused variable 't2' [-Wunused-variable] 96 | clock_t t2 = clock(); | ^~