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Leetcode
Medium
Trees
Binary Search
Minimum Absolute Difference in BST

Find the smallest absolute difference between values of any two nodes in a binary search tree.

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Problem Statement

Given the root of a binary search tree (BST), determine the minimum absolute difference between the values of any two distinct nodes.

Because values in a BST are ordered by an inorder traversal, the key is to compare neighboring values in sorted order rather than checking every pair.

Input Format

  • A binary search tree rooted at root.
  • Each node contains an integer value.

Output Format

  • Return a single integer: the minimum absolute difference between values of any two nodes in the tree.

Constraints

  • The tree contains at least 2 nodes.
  • Node values are integers.
  • The BST property holds for all nodes.
Examples
Sample cases returned by the problem API.

Example 1

Input

root = [4,2,6,1,3]

Output

1

Explanation

The inorder order is [1,2,3,4,6]. The smallest difference is min(2-1, 3-2, 4-3, 6-4) = 1.

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