给定一棵二叉树的先序遍历序列和中序遍历序列，要求计算该二叉树的高度。并生成代码

以下是给定先序遍历序列和中序遍历序列计算二叉树高度的代码实现。

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

def buildTree(preorder, inorder):
    if not inorder:
        return None
    root_val = preorder.pop(0)
    root = TreeNode(root_val)
    index = inorder.index(root_val)
    root.left = buildTree(preorder, inorder[:index])
    root.right = buildTree(preorder, inorder[index+1:])
    return root

def getHeight(root):
    if not root:
        return 0
    left_height = getHeight(root.left)
    right_height = getHeight(root.right)
    return max(left_height, right_height) + 1

preorder = [3, 9, 20, 15, 7]
inorder = [9, 3, 15, 20, 7]
root = buildTree(preorder, inorder)
print(getHeight(root))

输出结果为：

3

说明该二叉树的高度为 3。