Compilare: main.cpp: In function 'int main()': main.cpp:15:21: 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 = 0; i<s.size(); i++) | ~^~~~~~~~~ main.cpp:21:21: 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<s.size(); i++) | ~^~~~~~~~~ main.cpp:24:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 24 | while(st - 1 >= 0 && dr + 1 < s.size() && s[st - 1] == s[dr + 1]) | ~~~~~~~^~~~~~~~~~ main.cpp:35:37: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | while(st - 1 >= 0 && dr + 1 < s.size() && s[st - 1] == s[dr + 1]) | ~~~~~~~^~~~~~~~~~