Compilare: main.cpp: In function 'int main()': main.cpp:15:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 15 | for (int i = 1, k = 0;i < s.length();++i) { | ~~^~~~~~~~~~~~ main.cpp:26:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | for (int i = 0;i < pi.size();++i) { | ~~^~~~~~~~~~~