Reference for c++ learning

  #include <bits/stdc++.h> using namespace std ; int main (){ int t ; cin >> t ; while (t--){ string s ; cin >> s ; int sum{ 0 } ; for ( int i = 0 ; s [ i ] ; ++i) { if ( '0' <= s [ i ] && s [ i ] <= '9' ){ sum = sum + s [ i ] - '0' ; } } cout << sum << ' \n ' ; } return 0 ; }