Minimum Absolute Difference in BST
530. Minimum Absolute Difference in BST
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 {
* int val;
* TreeNode left;
* TreeNode right;
* TreeNode(int x) { val = x; }
* }
*/
public class Solution {
int min = Integer.MAX_VALUE;
TreeNode prev = null;
public int getMinimumDifference(TreeNode root) {
if (root == null) {
return min;
}
getMinimumDifference(root.left);
if (prev != null) {
min = Math.min(min, root.val - prev.val);
}
prev = root;
getMinimumDifference(root.right);
return min;
}
}
Hope this helps,
Michael