[LeetCode]: 108: Convert Sorted Array to Binary Search Tree

题目：

Given an array where elements are sorted in ascending order, convert it to a height balanced BST.

分析：

平衡二叉树的特点：左右子树的高度差不能超过1

采用二分查找思想和递归思想

代码：

    public static TreeNode sortedArrayToBST(int[] nums) {
        if(nums.length== 0){
            return null;
        }
        
        if(nums.length == 1){
            TreeNode rootNode = new TreeNode(nums[0]);
            return rootNode;
        }
        
        
        int intPosition =0;
        intPosition = nums.length/2;
        TreeNode rootNode = new TreeNode(nums[intPosition]);
        
        rootNode.left = sortedArrayToBST(Arrays.copyOfRange(nums, 0, intPosition));
        rootNode.right = sortedArrayToBST(Arrays.copyOfRange(nums, intPosition, nums.length));

        return rootNode;
    }

PS：这个题目简单就是因为输入的数组是排好序的