LeetCode in Net
530. Minimum Absolute Difference in BST
Easy
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/
Solution
using System;
using LeetCodeNet.Com_github_leetcode;
/**
* Definition for a binary tree node.
* public class TreeNode {
* public int val;
* public TreeNode left;
* public TreeNode right;
* public TreeNode(int val=0, TreeNode left=null, TreeNode right=null) {
* this.val = val;
* this.left = left;
* this.right = right;
* }
* }
*/
public class Solution {
private int ans = int.MaxValue;
private int? prev = null;
public int GetMinimumDifference(TreeNode root) {
InOrder(root);
return ans;
}
private void InOrder(TreeNode node) {
if (node == null) {
return;
}
InOrder(node.left);
if (prev != null) {
ans = Math.Min(ans, Math.Abs((int) node.val - prev.Value));
}
prev = node.val;
InOrder(node.right);
}
}