Description
https://leetcode.com/problems/minimum-distance-between-bst-nodes/
Given the root of a Binary Search Tree (BST), return the minimum difference between the values of any two different nodes in the tree.
Example 1:
Input: root = [4,2,6,1,3] Output: 1
Example 2:
Input: root = [1,0,48,null,null,12,49] Output: 1
Constraints:
- The number of nodes in the tree is in the range
[2, 100]. 0 <= Node.val <= 105
Note: This question is the same as 530: https://leetcode.com/problems/minimum-absolute-difference-in-bst/
Explanation
In order traverse to get values in ascending order. Then find the minimum distance between values.
Python Solution
# Definition for a binary tree node.
# class TreeNode:
# def __init__(self, val=0, left=None, right=None):
# self.val = val
# self.left = left
# self.right = right
class Solution:
def minDiffInBST(self, root: TreeNode) -> int:
self.values = []
self.inorder_traverse(root)
min_distance = sys.maxsize
prev = None
for val in self.values:
if prev:
distance = val - prev
min_distance = min(min_distance, distance)
prev = val
return min_distance
def inorder_traverse(self, root):
if not root:
return
self.inorder_traverse(root.left)
self.values.append(root.val)
self.inorder_traverse(root.right)
- Time Complexity: O(N).
- Space Complexity: O(N).