python 二叉链表实现树的遍历

二叉链表是二叉树的一种链式存储结构，每个节点包含三个域：数据域、左子树指针域和右子树指针域。二叉链表的遍历有三种方式：前序遍历、中序遍历和后序遍历。以下是 Python 代码实现：

class TreeNode:
    def __init__(self, val=0, left=None, right=None):
        self.val = val
        self.left = left
        self.right = right

class BinaryTree:
    def __init__(self):
        self.root = None

    def preOrder(self, root):
        if root:
            print(root.val, end=' ')
            self.preOrder(root.left)
            self.preOrder(root.right)

    def inOrder(self, root):
        if root:
            self.inOrder(root.left)
            print(root.val, end=' ')
            self.inOrder(root.right)

    def postOrder(self, root):
        if root:
            self.postOrder(root.left)
            self.postOrder(root.right)
            print(root.val, end=' ')

使用示例：

tree = BinaryTree()
tree.root = TreeNode(1)
tree.root.left = TreeNode(2)
tree.root.right = TreeNode(3)
tree.root.left.left = TreeNode(4)
tree.root.left.right = TreeNode(5)

print("Preorder traversal:")
tree.preOrder(tree.root)
print("\nInorder traversal:")
tree.inOrder(tree.root)
print("\nPostorder traversal:")
tree.postOrder(tree.root)

输出结果：

Preorder traversal:
1 2 4 5 3 
Inorder traversal:
4 2 5 1 3 
Postorder traversal:
4 5 2 3 1