Compilare: main.cpp: In function 'int main()': main.cpp:22:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | for (int i=0;i<a.size();i++){ | ~^~~~~~~~~ main.cpp:26:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | for (int i=0;i<a.size()-1;i++){ | ~^~~~~~~~~~~ main.cpp:30:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | for (int i=a.size()-1;i<b.size();i++){ | ~^~~~~~~~~