Return string of all 0 's  of length A
str = " " NEW_LINE for i in range ( A ) : NEW_LINE INDENT str += '0' NEW_LINE DEDENT return str NEW_LINE if ( K <= dp [ A - 1 ] [ B ] ) : NEW_LINE return "0" + KthString ( A - 1 , B , K , dp ) NEW_LINE else : NEW_LINE return "1" + KthString ( A , B - 1 , K - dp [ A - 1 ] [ B ] , dp ) NEW_LINE