算法学习之：python 完成二叉搜索树的创建，先序遍历，中序遍历和后序遍历

代码

class Node:
    def __init__(self,value):
        self.value = value
        self.left = None
        self.right = None
    def add(self,value):
        if value >= self.value:
            if self.right == None:
                self.right = Node(value)
            else:
                self.right.add(value)
        else:
            if self.left == None:
                self.left = Node(value)
            else:
                self.left.add(value)

class BinarySearchTree:
    def __init__(self,value):
        self.root = Node(value)
    def add(self,value):
        self.root.add(value)

    def preorder(self,T):
        if T != None:
            print(T.value)
            self.preorder(T.left)
            self.preorder(T.right)
    def inorder(self,T):
        if T != None:
            self.inorder(T.left)
            print(T.value)
            self.inorder(T.right)
    def postorder(self,T):
        if T != None:
            self.postorder(T.left)
            self.postorder(T.right)
            print(T.value)
if __name__ == '__main__':
    arr = [1,3,6,7,3,4,9,11]
    bT = BinarySearchTree(arr[0])
    for i in range(1,len(arr)):
        bT.add(arr[i])

    print(bT.preorder(bT.root))
    print(bT.inorder(bT.root))
    print(bT.postorder(bT.root))