Compilare: main.cpp: In function 'int main()': main.cpp:43:20: warning: comparison of integer expressions of different signedness: 'llint' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 43 | for ( i = 0; i < s.size(); i++ ) { | ~~^~~~~~~~~~ main.cpp:61:46: warning: array subscript has type 'char' [-Wchar-subscripts] 61 | fout << x << " " << id / 2 * f[s[pos]] + (id + 1) / 2 * f[invert(s[pos])] + part[pos] << '\n'; | ^ main.cpp:61:73: warning: array subscript has type 'char' [-Wchar-subscripts] 61 | fout << x << " " << id / 2 * f[s[pos]] + (id + 1) / 2 * f[invert(s[pos])] + part[pos] << '\n'; | ~~~~~~^~~~~~~~