题目链接

递归

/*** 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 {public TreeNode sortedArrayToBST(int[] nums) {TreeNode root = traversal(nums, 0, nums.length - 1);return root;}public TreeNode traversal(int[] nums, int left,int right){if(left > right){return null;}int mid = (left + right) / 2;TreeNode root = new TreeNode(nums[mid]);root.left = traversal(nums, left, mid - 1);root.right = traversal(nums, mid + 1, right);return root;}
}