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# Invert Binary Tree - LeetCode

Subramanya Chakravarthy

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
};
``````