#235 Invert a Binary Tree

easy

javascript

blind75

binary-tree

recursion

You are given the root of a binary tree. Transform the tree by flipping it horizontally (mirror image) and return its root.

To invert the tree, each node's left and right children should be swapped.

Constraints:

0 ≤ Number of nodes in the tree ≤ 100
-100 ≤ Node value ≤ 100

Examples:

// Example 1:

//      1              1

//    /   \          /   \

//   2     3   =>   3     2

//  / \   / \      / \   / \

// 4   5 6   7    7   6 5   4

const root1 = createTree([1, 2, 3, 4, 5, 6, 7]);
console.log(invertTree(root1));
// Output: [1, 3, 2, 7, 6, 5, 4]


// Example 2:

//   3        3

//  / \  =>  / \

// 2   1    1   2

const root2 = createTree([3, 2, 1]);
console.log(invertTree(root2));
// Output: [3, 1, 2]


// Example 3:

const root3 = createTree([]);
console.log(invertTree(root3));
// Output: []