Compilare: main.cpp: In function 'void manacher(std::string&, std::vector<long long int>&)': main.cpp:99:49: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 99 | while(0 <= i-len[i] && i+len[i] < s.size() && s[i - len[i]] == s[i + len[i]]) len[i]++; | ~~~~~~~~~^~~~~~~~~~