#108 - Convert Sorted Array to Binary Search Tree

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Problem Description

Given an integer array nums where the elements are sorted in ascending order, convert it to a height-balanced binary search tree.

Solution

/**
 * 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 {number[]} nums
 * @return {TreeNode}
 */
var sortedArrayToBST = function(nums) {
  if (!nums.length) return null;

  const middleIndex = Math.floor(nums.length / 2);
  const root = new TreeNode(nums[middleIndex]);
  root.left = sortedArrayToBST(nums.slice(0, middleIndex));
  root.right = sortedArrayToBST(nums.slice(middleIndex + 1));

  return root;
};