# Minimum Absolute Difference in BST Problem & Solution

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.

## C++ Solution

``````#pragma GCC optimize("Ofast")
#pragma GCC optimization("unroll-loops")
#pragma GCC optimization("max-inline-insns-recursive-auto")

static const int _=[](){ios::sync_with_stdio(false);cin.tie(nullptr);cout.tie(nullptr);return 0;}();

/**
* 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 getMinimumDifference(TreeNode* root) {
vector<int> traversal;
traverse(root, traversal);

int diff = numeric_limits<int>::max();
for (int i = 1; i < traversal.size(); ++i) {

// Doing a diff between consecutive elements because they're sorted.
diff = min(diff, abs(traversal[i - 1] - traversal[i]));
}

return diff;
}

private:
void traverse(TreeNode* root, vector<int>& traversal) {
if (root == nullptr) {
return;
}

// When traversing in-order, the nodes of a BST are sorted.
traverse(root->left, traversal);
traversal.push_back(root->val);
traverse(root->right, traversal);
}
};
``````