/** * Definition for a binary tree node. * public class TreeNode { * int val; * TreeNode left; * TreeNode right; * TreeNode() {} * TreeNode(int val) { this.val = val; } * TreeNode(int val, TreeNode left, TreeNode right) { * this.val = val; * this.left = left; * this.right = right; * } * } */ class Solution { private TreeNode sortedArrayToBST(int[] nums, int min, int max) { if (min > max) { return null; } int mid = (min + max) / 2; return new TreeNode( nums[mid], sortedArrayToBST(nums, min, mid - 1), sortedArrayToBST(nums, mid + 1, max) ); } public TreeNode sortedArrayToBST(int[] nums) { return sortedArrayToBST(nums, 0, nums.length - 1); } }