question: public static void pack ( int [ ] n , String s ) { for ( int i = 0 ; i < n . length ; i ++ ) { n [ i ] = 0 ; } int idx = n . length - 1 ; for ( int i = s . length ( ) - 1 ; i >= 0 ; i -- ) { n [ idx -- ] = s . charAt ( i ) - '0' ; } }
target:  Pack from string into array.