108-Convert-Sorted-Array-to-Binary-Search-Tree.py

# Definition for a binary tree node.
# class TreeNode:
#     def __init__(self, val=0, left=None, right=None):
#         self.val = val
#         self.left = left
#         self.right = right
class Solution:
    def sortedArrayToBST(self, nums: List[int]) -> Optional[TreeNode]:

        def helper(left,right):
            if left > right:
                return None

            mid = (left + right) // 2
            
            return TreeNode(nums[mid], helper(left,mid-1), helper(mid+1,right))
            
        return helper(0,len(nums)-1)