Given a binary search tree with non-negative values, find the minimum absolute difference between values of any two nodes.
Example:
Input:
1 \ 3 / 2
Output: 1
Explanation: The minimum absolute difference is 1, which is the difference between 2 and 1 (or between 2 and 3).
Note:
There are at least two nodes in this BST.
/**
* 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 {
int min = int.MaxValue;
int? prev = null;
public int GetMinimumDifference(TreeNode root) {
InOrder(root);
return min;
}
private void InOrder(TreeNode root){
if(root == null){
return;
}
InOrder(root.left);
if(prev!=null){
min = Math.Min(Math.Abs(root.val-(int)prev),min);
}
prev = root.val;
InOrder(root.right);
}
}Time Complexity: O(n)
Space Complexity: O(1)
