Update 8_binary_tree.py

Author: devarakondapranav

set3/8_binary_tree.py

@@ -1,65 +1,65 @@
 class BinaryTreeNode:
+	#implments a complete binary tree
 	def __init__(self, value, left=None, right=None):
-		self.value=value;
-		self.left = left
-		self.right = right
+		self.value=value;		
+		self.nodes = [self.value]
 
 	def __add__(self, other):
-		if(self.left == None):
-			self.left = other
-			print("Added " +str(other.value) + " as left child of " + str(self.value))
-		elif(self.right == None):
-			self.right = other
-			print("Added " +str(other.value) + " as right child of " + str(self.value))
-		else:
-			print("The current node is not vacant")
-
-	def __sub__(self, other):
-		if(self.left == other):
-			self.left = None
-			print("Deleted the left node of " + str(self.value))
-		elif(self.right == other):
-			self.right = None
-			print("Deleted the right node of" + str(self.value))
-		else:
-			print(str(other.value) +" is not a child of " + str(self.value))
-
-	def printTree(self, root):
-		#inorder traversal of the tree
-		print(root.value)
-		if(root.left !=None):
-			self.printTree(root.left)
-		if(root.right!=None):
-			self.printTree(root.right)
-
-root = BinaryTreeNode(1)
-a = BinaryTreeNode(2)
-b = BinaryTreeNode(3)
-c = BinaryTreeNode(4)
+		#Nodes are added to the end of the tree as in CBT
+		self.nodes.append(other.value)
+		#print("Node added at the end of the tree")
 
-root+a#a is added as left child of root
-root+b#b is added as right child of root
-b + c#c is added as the left child of b
 
-'''Tree is now
-      1
-     /  \
-    2    3
-   /
-  4
-'''
+			
 
-root.printTree(root)
-
-b-c#c is removed as the left child of b
+	def __sub__(self, other):
+		#Since there are no constraints on how to delete nodes 
+		#the specified node is deleted and the last node in the tree is put in its place
+		if other.value not in self.nodes:
+			print(str(other.value) + " is not in the tree")
+		else:
+			curPosition = self.nodes.index(other.value)
+			self.nodes[curPosition] = self.nodes[-1]
+			self.nodes.remove(self.nodes[-1])
+			print("Node is " + "Deleted")
+			if(len(self.nodes) == 0):
+				root = None
 
-'''Tree is now
-      1
-     /  \
-    2    3
-'''
 
-root.printTree(root)
+	def printTree(self, root):
+		#level order traversal
+		if(root==None):
+			print("Tree is empty")
+		print("*********")
+		for i in range(len(self.nodes)):
+			print(self.nodes[i], end = " ")
+		print(" ")	
+		print("*********")
+			
+root = None
+while(True):
+	print("Select on option")
+	print("1. Insert a node")
+	print("2. Delete a node")
+	print("3. Print the tree")
+	choice = int(input())
+	if(choice ==1):
+		if(root==None):
+			root = BinaryTreeNode(int(input('Enter the value to insert...')))
+			print("Done inserting at the root")
+		else:
+			root + BinaryTreeNode(int(input('Enter the value to insert...')))
+			print("Node is inserted")
+	elif(choice == 2):
+		root - BinaryTreeNode(int(input("Enter the node to be deleted")))
+	elif(choice ==3):
+		if(root==None):
+			print("Tree is empty")
+		else:
+			print("The tree is ")
+			root.printTree(root)
+	else:
+		print("Choose a valid option")