# Minimum Absolute Difference In BST Problem

## Description

LeetCode Problem 530.

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:

``````1
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Input: root = [4,2,6,1,3]
Output: 1
``````

Example 2:

``````1
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, 10^4].
• 0 <= Node.val <= 10^5

## Sample C++ Code

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/**
* Definition for a binary tree node.
* struct TreeNode {
*     int val;
*     TreeNode *left;
*     TreeNode *right;
*     TreeNode() : val(0), left(nullptr), right(nullptr) {}
*     TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
*     TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
* };
*/
class Solution {
public:
int inorderTraverse(TreeNode* root, int& val, int& min_dif) {
if (root->left != NULL)
inorderTraverse(root->left, val, min_dif);
if (val >= 0)
min_dif = min(min_dif, root->val - val);
val = root->val;
if (root->right != NULL)
inorderTraverse(root->right, val, min_dif);
return min_dif;
}

int getMinimumDifference(TreeNode* root) {
auto min_dif = INT_MAX, val = -1;
return inorderTraverse(root, val, min_dif);
}
};
``````