CODEWITHSUNDEEP
pythonarraysbinary-search-tree
Castagordo
Castagordo

Reputation: 21

Array To Binary Search Tree

I need to create a function that creates a BST from an array, in python. The array is already sorted.

The example is:

function array_to_binary_search_tree(array, start, end)
    if start > end
        Return an empty value
    mid := int((start + end) / 2)
    tree := BinaryTree()
    tree.node := array[mid]
    tree.left := array_to_binary_search_tree(array, start, mid - 1)
    tree.right := array_to_binary_search_tree(array, mid + 1, end)
    Return 'tree'

I have this:

class BST:

def __init__(self,tree,info):
    self.right = None
    self.left = None
    self.info = info

    def arrayToBST(seq):
    if (seq == []):
        return None
    mid = ((len(seq)) // 2)
    tree = BST(seq[mid])
    tree.left = arrayToBST(seq[0:mid])
    tree.right = arrayToBST(seq[mid+1:])

    return tree

if __name__ == "__main__":
    seq = [1,2,3,4,5,6,7,8,9]
    arrayToBST(seq)

The result is:

NameError: name 'arrayToBST' is not defined

I don't see the error. Please help, thanks!

Upvotes: 2

Views: 1600

Answers (1)

kindall
kindall

Reputation: 184345

In your recursive call, you are calling the arrayToBST method of an instance. Therefore, you need to call self.arrayToBST not just arryToBST. The entire point of self is to let you access attributes on your instance.

You should also create an instance and call that instance's arrayToBST method in your main section.

Upvotes: 1

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