Skip to main content

Minimum Distance Between BST Nodes

Problem statement​

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/

My solution​

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @return {number}
 */
var minDiffInBST = function(root) {
    let prev = null;
    let min = Infinity;
    
    const recursiveFuncton = node => {
        if (node === null) {return}
        
        recursiveFuncton(node.left);
        
        if (prev) {
            min = Math.min(min, Math.abs(node.val - prev.val));
        }
        prev = node;
        
        recursiveFuncton(node.right);
    };
    
    recursiveFuncton(root);
    return min;
};