题目

给你一个二叉搜索树的根节点root，返回树中任意两不同节点值之间的最小差值。

思路

image.png

语雀内容

  1. # Definition for a binary tree node.
  2. # class TreeNode:
  3. #     def __init__(self, val=0, left=None, right=None):
  4. #         self.val = val
  5. #         self.left = left
  6. #         self.right = right
  7. class Solution:
  8.     def minDiffInBST(self, root: TreeNode) -> int:
  9.         def dfs(root):
  10.             if root is None:
  11.                 return
  13.             dfs(root.left)
  15.             if self.preVal == -1:
  16.                 self.preVal = root.val
  17.             else:
  18.                 self.minDiff = min(self.minDiff, root.val - self.preVal)
  19.                 self.preVal = root.val
  21.             dfs(root.right)
  23.         self.minDiff = float('INF')
  24.         self.preVal = -1
  25.         dfs(root)
  27.         return self.minDiff