# Increasing Order Search Tree

# 897. Increasing Order Search Tree

Given the root of a binary search tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only one right child.

```### Example 1:
```
Input: root = [5,3,6,2,4,null,8,1,null,null,null,7,9]
Output: [1,null,2,null,3,null,4,null,5,null,6,null,7,null,8,null,9]
```
```
```### Example 2:
```
Input: root = [5,1,7]
Output: [1,null,5,null,7]
```
```
```Constraints:
```
The number of nodes in the given tree will be in the range [1, 100].
0 <= Node.val <= 1000
```
```
```/**
* Definition for a binary tree node.
* function TreeNode(val, left, right) {
*     this.val = (val===undefined ? 0 : val)
*     this.left = (left===undefined ? null : left)
*     this.right = (right===undefined ? null : right)
* }
*/
/**
* @param {TreeNode} root
* @return {TreeNode}
*/
var increasingBST = function(root) {

const out = new TreeNode();
let cur = out;

const inOrderTraverse = (node) => {
if (!node) {
return;
}

inOrderTraverse(node.left);

node.left = null;
cur.right = node;
cur = node;
inOrderTraverse(node.right);
}

inOrderTraverse(root);
return out.right;
};
```