701. Insert into a Binary Search Tree——tree
题目分析:val值比当前值小向左查找,否则向右查找,否则插入
# Definition for a binary tree node.
# class TreeNode(object):
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution(object):
def insertIntoBST(self, root, val):
"""
:type root: TreeNode
:type val: int
:rtype: TreeNode
"""
if not root:
return TreeNode(val)
if val < root.val:
root.left = self.insertIntoBST(root.left, val)
elif val > root.val:
root.right = self.insertIntoBST(root.right, val)
return root