Compilare: main.cpp: In function 'int main()': main.cpp:20:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 20 | for (int i = 1; i < a.size(); i++) | ~~^~~~~~~~~~ main.cpp:25:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 25 | while (p1 >= 0 and p2 <= a.size() and a[p1] == a[p2]) | ~~~^~~~~~~~~~~ main.cpp:45:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 45 | while (p1 >= 0 and p2 <= a.size() and a[p1] == a[p2]) | ~~~^~~~~~~~~~~ main.cpp:57:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 57 | for (int i = 1; i <= a.size(); i++) | ~~^~~~~~~~~~~