text: Finding sum of digits in current prime factor pf [ i ] .
code: int pf_sum ; for ( pf_sum = 0 ; pf . get ( i ) > 0 ; pf_sum += pf . get ( i ) % 10 , pf . set ( i , pf . get ( i ) / 10 ) ) ; all_pf_sum += pf_sum ; }