Given a binary tree, you have to invert left and right nodes of it

**Example**:

*Input*

```
4
```

/

2 7
/ \ /

1 3 6 9

*Output*

```
4
```

/

7 2
/ \ /

9 6 3 1

**Algorithm:**

The intuition here is for each root node you visit swap left and right

The code would be something like

```
temp = root.left
root.left = root.right
root.right = temp
```

And we have to do this recursively for all the nodes

**Code**

```
/**
* 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 invertTree = function(root) {
// If there is a root we swap it and if there is no root just return the value
if(root) {
let temp = root.left
root.left = root.right
root.right = temp
invertTree(root.left)
invertTree(root.right)
}
return root
};
```