Tag: tree

class Node:
    def __init__(self, data, left=None, right=None):
        self.data = data
        self.left = left
        self.right = right
 
def inorderTraversal(root):
 
    if root is None:
        return
 
    inorderTraversal(root.left)
    print(root.data, end=' ')
    inorderTraversal(root.right)
 
def preorderTraversal(root):
 
    if root is None:
        return
 
    print(root.data, end=' ')
    preorderTraversal(root.left)
    preorderTraversal(root.right)
 
def construct(start, end, preorder, pIndex, dict):
 
    # base case
    if start > end:
        return None, pIndex
 
    root = Node(preorder(pIndex))
    pIndex = pIndex + 1
 
    index = dict(root.data)
 
    root.left, pIndex = construct(start, index - 1, preorder, pIndex, dict)
 
    root.right, pIndex = construct(index + 1, end, preorder, pIndex, dict)
 
    return root, pIndex     

def constructTree(inorder, preorder):
 
    dict = {}
    for i, e in enumerate(inorder):
        dict(e) = i
 
    pIndex = 0
 
    return construct(0, len(inorder) - 1, preorder, pIndex, dict)(0)
 
 
if __name__ == '__main__':
 
 
    inorder = (4, 2, 1, 7, 5, 8, 3, 6)
    preorder = (1, 2, 4, 3, 5, 7, 8, 6)
 
    root = constructTree(inorder, preorder)
 
    print("The inorder traversal is ", end='')
    inorderTraversal(root)
 
    preorderTraversal(root)

I have this code which construct the binary tree, but in no way it can display the tree in the terminal. It is hard to do! Is there anyone here who could add a method which can display the binary tree in a terminal?

For the above example, it might look like

Binary Tree