python實現二叉尋找樹

# -*- coding: cp936 -*-#---------------------------------------------#                                             # author  chile                                   # version  1.0                                # date  2014-02-17                                       # desc 二叉樹                      #                                             #                                            #                                            #---------------------------------------------class bintree:    def __init__(self):        self.root = None            # 前驅節點    def treePredecessor(self,entry):        if entry.left != None:            return self.maxTree(entry.left)        preNode = entry.parent        tempNode = entry        while preNode != None and preNode.right.value != entry.value:            tempNode = preNode            preNode = preNode.parent        return preNode                #後繼節點          def treeSuccessor(self,entry):        if entry.right != None:            return self.minTree(entry.right)        preNode = entry.parent        tempNode = entry        while preNode != None and preNode.left.value != entry.value:            tempNode = preNode            preNode = preNode.parent        return preNode        def add(self,value):        tempNode = self.root        parentNode = None        entry = bintree.entry(value = value)        while tempNode != None:            parentNode = tempNode            if cmp(value,parentNode.value) < 0:                tempNode = tempNode.left            else:                tempNode = tempNode.right        if parentNode == None:            self.root = entry        elif cmp(value,parentNode.value) < 0:            parentNode.left = entry            entry.parent = parentNode        else:            parentNode.right = entry            entry.parent = parentNode        #這裡刪除是全部刪除節點（包括所有子節點）    def remove(self,value):        root = self.root        parentNode = None        if value == root.value:            root.left = None            root.right = None        while root != None:            parentNode = root.parent            if value == root.value:                root.left = None                root.right = None                if parentNode.left != None and parentNode.left.value == value:                    parentNode.left = None                    break                else:                    parentNode.right = None                    break            elif cmp(value,root.value) < 0:                root = root.left            else:                root = root.right        #尋找節點    def search(self,value):        root = self.root        while root != None and root.value != value:            if cmp(value,root.value) < 0:                root = root.left            else:                root = root.right        return root        #最小值的節點，其實就是找左邊的葉子節點    def minTree(self,root):        entry = root        while entry.left != None:            entry = entry.left        return entry        #最大值的節點    def maxTree(self,root):        entry = root        while entry.right != None:            entry = entry.right        return entry                        #中序遍曆    def iterator(self,root):        if root != None:            self.iterator(root.left)            print root.value            self.iterator(root.right)                class entry:        def __init__(self, value=None):            self.left = None            self.right = None            self.parent = None            self.value = value            arr = [15,5,3,12,10,13,6,7,16,20,18,23]tree = bintree()for val in arr:    tree.add(val) tree.iterator(tree.root)node = tree.search(16)print node.left , node.right , node.parent.valueprint tree.maxTree(node).valueprint tree.treePredecessor(node).valueprint tree.treeSuccessor(node).value#print tree.maxTree() , tree.minTree()

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