LeetCode 700 Search in a Binary Search Tree 解題報告
題目要求
Given the root node of a binary search tree (BST) and a value. You need to find the node in the BST that the node‘s value equals the given value. Return the subtree rooted with that node. If such node doesn‘t exist, you should return NULL.
題目分析及思路
題目給出一棵二叉樹和一個數值，要求找到與該數值相等的結點並返回以該結點為根結點的子樹。可以使用隊列保存結點，再將結點循環彈出進行判斷。
python代碼?
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, x):
# self.val = x
# self.left = None
# self.right = None
class Solution:
def searchBST(self, root, val):
"""
:type root: TreeNode
:type val: int
:rtype: TreeNode
"""
q = collections.deque()
q.append(root)
while q:
node = q.popleft()
if not node:
continue
if node.val != val:
q.append(node.left)
q.append(node.right)
continue
else:
return node
return None
LeetCode 700 Search in a Binary Search Tree 解題報告