pgm10_18.txt

Data Structures And Algorithms With Object-Oriented Design Patterns In Python (2003) source code and

#
# This file contains the Python code from Program 10.18 of
# "Data Structures and Algorithms
# with Object-Oriented Design Patterns in Python"
# by Bruno R. Preiss.
#
# Copyright (c) 2003 by Bruno R. Preiss, P.Eng.  All rights reserved.
#
# http://www.brpreiss.com/books/opus7/programs/pgm10_18.txt
#
class MWayTree(SearchTree):

    def withdraw(self, obj):
        if self.isEmpty:
            raise KeyError
        index = self.findIndex(obj)
        if index != 0 and self._key[index] == obj:
            if not self._subtree[index - 1].isEmpty:
                max = self._subtree[index - 1].max
                self._key[index] = max
                self._subtree[index - 1].withdraw(max)
            elif not self._subtree[index].isEmpty:
                min = self._subtree[index].min
                self._key[index] = min
                self._subtree[index].withdraw(min)
            else:
                self._count = self._count - 1
                i = index
                while i <= self._count:
                    self._key[i] = self._key[i + 1]
                    self._subtree[i] = self._subtree[i + 1]
                    i = i + 1
                self._key[i] = None
                self._subtree[i] = None
                if self._count == 0:
                    self._subtree[0] = None
        else:
            self._subtree[index].withdraw(obj)

    # ...