#NEWLINE# def isAdditiveNumber( self , num ) : #NEWLINE# #INDENT# '\n        Backtracking\n        :type num: str\n        :rtype: bool\n        ' #NEWLINE# n = len ( num ) #NEWLINE# for i in xrange ( 1 , n ) : #NEWLINE# #INDENT# for j in xrange ( i , n ) : #NEWLINE# #INDENT# if self . predicate ( num , 0 , i , j ) : #NEWLINE# #INDENT# return True #NEWLINE# #UNINDENT# #UNINDENT# #UNINDENT# return False