convert-sorted-array-to-binary-search-tree.js

/**
 * 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 mid = Math.floor(nums.length / 2);
    const root = new TreeNode(nums[mid]);

    // Call the function recursively on each subtree
    
    root.left = sortedArrayToBST(nums.slice(0, mid));
    root.right = sortedArrayToBST(nums.slice(mid + 1));

    return root;
    
};