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.
1 /** 2 * Definition for a binary tree node. 3 * public class TreeNode { 4 * int val; 5 * TreeNode left; 6 * TreeNode right; 7 * TreeNode(int x) { val = x; } 8 * } 9 */ 10 public class Solution { 11 int min = Integer.MAX_VALUE; 12 Integer prev = null; 13 14 public int getMinimumDifference(TreeNode root) { 15 if (root == null) return min; 16 17 getMinimumDifference(root.left); 18 19 if (prev != null) { 20 min = Math.min(min, root.val - prev); 21 } 22 prev = root.val; 23 24 getMinimumDifference(root.right); 25 26 return min; 27 } 28 29 }
Minimum Absolute Difference in BST
原文：http://www.cnblogs.com/amazingzoe/p/6480751.html