Compilare: main.cpp: In function 'int main()': main.cpp:21:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 21 | for(int i=0; i<sir.size(); ++i) { | ~^~~~~~~~~~~ main.cpp:28:37: 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(; i-raza >= 0 && i+raza < sir.size() && sir[i-raza] == sir[i+raza]; ++raza); | ~~~~~~~^~~~~~~~~~~~