Compilare: main.cpp: In function 'void buildPi(std::string, int*)': main.cpp:27:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 27 | for(int i=1, j=0; i<s.length(); i++){ | ~^~~~~~~~~~~ main.cpp: In function 'int32_t main()': main.cpp:63:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 63 | for(int i=0; i<res.size(); i++){ | ~^~~~~~~~~~~