#108将有序数组转换为二叉搜索树

import java.util.*;

class TreeNode {
    int val;
    TreeNode left;
    TreeNode right;

    TreeNode(int val) {
        this.val = val;
    }
}

class Solution {
    public TreeNode sortedArrayToBST(int[] nums) {
        return build(nums, 0, nums.length - 1);
    }

    private TreeNode build(int[] nums, int left, int right) {
        if (left > right) return null;
        int middle = left + (right - left) / 2;
        TreeNode root = new TreeNode(nums[middle]);
        root.left = build(nums, left, middle - 1);
        root.right = build(nums, middle + 1, right);
        return root;
    }
}