Given a Binary Search Tree (BST) with the root node root, return the minimum difference between the values of any two different nodes in the tree.
Example :
Input: root = [4,2,6,1,3,null,null]
Output: 1
Explanation:
Note that root is a TreeNode object, not an array.
The given tree [4,2,6,1,3,null,null] is represented by the following diagram:
4
/ 2 6
/ \
1 3
while the minimum difference in this tree is 1, it occurs between node 1 and node 2, also between node 3 and node 2.
Note:
100.# 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 minDiffInBST(self, root):
"""
:type root: TreeNode
:rtype: int
"""
diff=100000
last_visited=None
stack=[]
node=root
while node or stack:
if node:
stack.append(node)
node=node.left
else:
node=stack.pop()
if last_visited and abs(last_visited.val-node.val)<diff:
diff=abs(last_visited.val-node.val)
last_visited=node
node=node.right
return diff
[LeetCode&Python] Problem 783. Minimum Distance Between BST Nodes
原文：https://www.cnblogs.com/chiyeung/p/10011051.html