Compilare: main.cpp: In function 'void solve()': main.cpp:58:18: warning: comparison of integer expressions of different signedness: '__gnu_cxx::__alloc_traits<std::allocator<int>, int>::value_type' {aka 'int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 58 | if(pi[i] == a.length()){ main.cpp:66:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 66 | for(int i = 0; i < ans.size(); ++i){ | ~~^~~~~~~~~~~~