invert-binary-tree.js

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @return {TreeNode}
 */
// Solution 1
var invertTree = function (root) {
    if (root) {
        var temp = root.right;
        root.right = root.left;
        root.left = temp;
        invertTree(root.left);
        invertTree(root.right);
        return root;
    } else {
        return root;
    }
};

//Solution 2
/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @return {TreeNode}
 */
var invertTree = function (root) {
    if (root === null) {
        return root;
    } else if (root.left === null && root.right === null) {
        return root
    } else {
        var temp = root.right;
        root.right = root.left;
        root.left = temp;
        invertTree(root.left);
        invertTree(root.right);
        return root;
    }
};