Compilare: main.cpp: In function 'int main()': main.cpp:21:23: 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 = 1; i < a.size(); i++) | ~~^~~~~~~~~~ main.cpp:26:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | while (p1 >= 0 and p2 < a.size() and a[p1] == a[p2]) | ~~~^~~~~~~~~~ main.cpp:46:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 46 | while (p1 >= 0 and p2 < a.size() and a[p1] == a[p2]) | ~~~^~~~~~~~~~ main.cpp:58:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 58 | for (int i = 1; i < a.size(); i++) | ~~^~~~~~~~~~