108. Convert Sorted Array to Binary Search Tree 

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
class Solution {
    public TreeNode sortedArrayToBST(int[] nums) {
        return sortedArrayToBST(nums, 0, nums.length - 1);
    }

    private TreeNode sortedArrayToBST(int[] nums, int left, int right) {
        if (left > right) {
            return null;
        }

        int mid = (left + right) >>> 1;
        TreeNode root = new TreeNode(nums[mid]);
        root.left = sortedArrayToBST(nums, left, mid - 1);
        root.right = sortedArrayToBST(nums, mid + 1, right);
        return root;
    }
}

References

108. Convert Sorted Array to Binary Search Tree