Compilare: main.cpp: In function 'void solve()': main.cpp:47:27: 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] 47 | for (int j = 0; j < v[i].size(); j++) { | ~~^~~~~~~~~~~~~ main.cpp:66:37: 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] 66 | for (int j = len - 1; j < v[i].size(); j++) { | ~~^~~~~~~~~~~~~