numbers.cpp: In function 'bool good(std::string)':
numbers.cpp:17:26: 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]
17 | for (ll i = 0; i + 1 < a.size(); i++)
| ~~~~~~^~~~~~~~~~
numbers.cpp:19:26: 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]
19 | for (ll i = 0; i + 2 < a.size(); i++) if (a[i] == a[i + 2]) return false;
| ~~~~~~^~~~~~~~~~
numbers.cpp: In function 'long long int f(long long int)':
numbers.cpp:29:22: 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]
29 | for (ll i = 0; i < a.size(); i++)
| ~~^~~~~~~~~~
numbers.cpp:39:30: 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]
39 | for (ll i = 1; i + 1 < a.size(); i++) ans += 9 * 9 * pw[a.size() - i - 2];
| ~~~~~~^~~~~~~~~~