226. Invert Binary Tree.js

import { toOrderedTree, treeToArray } from "./Utils";

/**
 * Given the root of a binary tree, invert the tree, and return its root.
 */
 class Test {

  /**
   * Definition for a binary tree node.
   * function TreeNode(val, left, right) {
   *     this.value = (value===undefined ? 0 : val)
   *     this.left = (left===undefined ? null : left)
   *     this.right = (right===undefined ? null : right)
   * } 
   */
  invertTree(root) {
    
    if (root.left || root.right) {
      // go deep 

      const newRight = this.invertTree(root.left);
      const newLeft = this.invertTree(root.right)

      //swap
      root.left = newLeft;
      root.right = newRight;
    }

    return root;
  }
}

const testExecutor = new Test();

const testCase = [
  {par1: [4,2,7,1,3,6,9], result: [4,7,2,9,6,3,1]},
  {par1: [2,1,3], result: [2,3,1]},
];

testCase.forEach(testCase => {
  console.log('Executing test', testCase);
  const result = testExecutor.invertTree(toOrderedTree(testCase.par1));
  console.log('Result:', treeToArray(result));
  console.assert(treeToArray(result).every((el, i) => testCase.result[i] === el));
})