Question

TestCodeForAssigment.py
def main():
    # testing recursive find, pre- and post-order, and __len__

    """ creating the following BST:
                           25
                  15                29
            12         20      27        50
                    17 """
    t1 = BST()
    t1.insert_rec(25)
    t1.insert_rec(15)
    t1.insert_rec(12)
    t1.insert_rec(20)
    t1.insert_rec(17)
    t1.insert_rec(29)
    t1.insert_rec(27)
    t1.insert_rec(50)

    print("Let's see if we can find 27 using the non-recursive find: ", t1.find(27))
    print("Let's see if we can find 27 using the recursive find: ", t1.findRecursive(27))

    print("The length of the BST tree is ",t1.__len__())

    print("The preorder traversal of the tree:", list(t1.preOrder()))

    print("The postorder traversal of the tree:", list(t1.postOrder()))

main()

Test your code, you can use for these:TestCodeForAssigment.py

2. Consider the binary search tree from the left side of Figure 7.8 (before the 6 is deleted). List the order that the nodes would be visited for each traversal order (preorder, in-order, and postorder). 3. Write an invariant for the BST class

Answer 1

binarySearchTree.py

class bst:
def __init__(self,data):
self.left=None
self.right=None
self.data=data
#insert data int BST   
def insert(root,data):
newnode=bst(data)
if root is None:
root=newnode
else:
if root.data < newnode.data:
if root.right is None:
root.right=newnode
else:
root.right.insert(data)
else:
if root.left is None:
root.left=newnode
else:
root.left.insert(data)
  
def inorder(root):
if root:
if root.left is not None:
root.left.inorder()
print(root.data,end=" ")
if root.right is not None:
root.right.inorder()
  
def preOrder(root):
if root:
print(root.data,end=" ")
if root.left is not None:
root.left.inorder()
if root.right is not None:
root.right.inorder()
  
def postOrder(root):
if root:
if root.left is not None:
root.left.inorder()
if root.right is not None:
root.right.inorder()
print(root.data,end=" ")

#find size of BST Recursively   
def size(root):
treeSize=0
if root is not None:
treeSize+=1
  
if root.left is not None:
treeSize+=root.left.size()
if root.right is not None:
treeSize+=root.right.size()
return treeSize
  
#Recursive search in BST
def findRecursive(root,data):
if root:
if(root.data==data):
return True
if root.left is not None and root.data>data:
return root.left.findRecursive(data)
if root.right is not None and root.data < data:
return root.right.findRecursive(data)
return False
  
#Search without Recursion
def find(root,data):
while root is not None:
if(root.data==data):
return True
if root.data>data:
root=root.left
if root.data < data:
root=root.right
return False   

if __name__=="__main__":
root=bst(25)
root.insert(15)
root.insert(20)
root.insert(29)
root.insert(12)
root.insert(17)
root.insert(50)
root.insert(27)
print("The inorder traversal of the tree : ",end=" ")
root.inorder()

print("\nLet's see if we can find 27 using the non-recursive find: ",root.find(27))
print("\nLet's see if we can find 27 using the recursive find: ", root.findRecursive(27))

print("\nThe length of the BST tree is ",root.size())

print("\nThe preorder traversal of the tree:",end=" ")
root.preOrder()

print("\nThe postorder traversal of the tree:",end=" ")
root.postOrder()

# Complex

  

OUTPUT