Python Binary Search Tree: Create a Balanced Binary Search Tree (BST) using an sorted array

Last update on December 21 2024 07:26:10 (UTC/GMT +8 hours)

Write a Python program to create a Balanced Binary Search Tree (BST) using an array of elements where array elements are sorted in ascending order.

Pictorial Presentation:

Sample Solution:

Python Code:

class TreeNode(object):
    def __init__(self, x):
        self.val = x
        self.left = None
        self.right = None

def sorted_array_to_bst(nums):
    
    if not nums:
        return None
    mid_val = len(nums)//2
    node = TreeNode(nums[mid_val])
    node.left = sorted_array_to_bst(nums[:mid_val])
    node.right = sorted_array_to_bst(nums[mid_val+1:])
    return node

def preOrder(node): 
    if not node: 
        return      
    print(node.val)
    preOrder(node.left) 
    preOrder(node.right)   
    
result = sorted_array_to_bst([1, 2, 3, 4, 5, 6, 7])
preOrder(result)

Sample Output:

4
2
1
3
6
5
7

Flowchart:

Python Code Editor:

Contribute your code and comments through Disqus.

Previous: Binary Tree Home.
Next: Write a Python program to find the closest value of a given target value in a given non-empty Binary Search Tree (BST) of unique values.