Description
https://leetcode.com/problems/minimum-absolute-difference-in-bst/
Given the root of a Binary Search Tree (BST), return the minimum absolute 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, 104]. 0 <= Node.val <= 105
Note: This question is the same as 783: https://leetcode.com/problems/minimum-distance-between-bst-nodes/
Explanation
Traverse to get node values and then find the minimum distance between node 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 getMinimumDifference(self, root: TreeNode) -> int:
self.results = []
self.traverse(root)
self.results = sorted(self.results)
prev = None
min_distance = sys.maxsize
for val in self.results:
if prev != None:
min_distance = min(min_distance, val - prev)
prev = val
return min_distance
def traverse(self, root):
if not root:
return
self.results.append(root.val)
self.traverse(root.left)
self.traverse(root.right)- Time Complexity: O(N).
- Space Complexity: O(N).