Compilare: main.cpp: In function 'int main()': main.cpp:38:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 38 | for(int i = a.size()+1; i < s.size(); ++i) { | ~~^~~~~~~~~~ main.cpp:39:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 39 | if(z[i] == a.size()) { | ~~~~~^~~~~~~~~~~