Compilare: main.cpp: In function 'int main()': main.cpp:17:28: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 17 | for(int j = ini / 2; j < a.size(); ++j) | ~~^~~~~~~~~~ main.cpp:20:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 20 | while(st >= 0 && dr < a.size() && a[st] == a[dr]) | ~~~^~~~~~~~~~ main.cpp:22:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | if(dr == a.size()) | ~~~^~~~~~~~~~~ main.cpp:30:29: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 30 | while(st >= 0 && dr < a.size() && a[st] == a[dr]) | ~~~^~~~~~~~~~ main.cpp:32:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 32 | if(dr == a.size()) | ~~~^~~~~~~~~~~