Compilare: main.cpp: In function 'void solve()': main.cpp:12:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 12 | for(int i=0;i<s.size();i++){ | ~^~~~~~~~~ main.cpp:15:27: 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] 15 | if(frecv[s[i]-'a']>s.size()/2){ main.cpp:22:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 22 | for(int j=0;j<s.size();j++){ | ~^~~~~~~~~