Compilare: main.cpp: In function 'bool check(int)': main.cpp:19:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 19 | if (x >= h[index[1]].size()) { | ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp:23:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 23 | if (x >= h[index[i]].size() || h[index[1]][x] != h[index[i]][x]) { | ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:55:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 55 | for (int j = 1; j < s.size(); j++) { | ~~^~~~~~~~~~