Create Top_View_Of_Binary_Tree.py

rockani · techyminati · commit 8c50d8a2cfff · 2022-10-24T09:55:08.000+05:30
Adding python file
diff --git a/Top_View_Of_Binary_Tree.py b/Top_View_Of_Binary_Tree.py
@@ -0,0 +1,81 @@
+# Python3 program to print top
+# view of binary tree
+
+# Binary Tree Node
+""" utility that allocates a newNode
+with the given key """
+
+
+class newNode:
+
+	# Construct to create a newNode
+	def __init__(self, key):
+		self.data = key
+		self.left = None
+		self.right = None
+		self.hd = 0
+
+# function should print the topView
+# of the binary tree
+
+
+def topview(root):
+
+	if(root == None):
+		return
+	q = []
+	m = dict()
+	hd = 0
+	root.hd = hd
+
+	# push node and horizontal
+	# distance to queue
+	q.append(root)
+
+	while(len(q)):
+		root = q[0]
+		hd = root.hd
+
+		# count function returns 1 if the
+		# container contains an element
+		# whose key is equivalent to hd,
+		# or returns zero otherwise.
+		if hd not in m:
+			m[hd] = root.data
+		if(root.left):
+			root.left.hd = hd - 1
+			q.append(root.left)
+
+		if(root.right):
+			root.right.hd = hd + 1
+			q.append(root.right)
+
+		q.pop(0)
+	for i in sorted(m):
+		print(m[i], end="")
+
+
+# Driver Code
+if __name__ == '__main__':
+
+	""" Create following Binary Tree
+		1
+		/ \
+	2 3
+		\
+		4
+		\
+			5
+			\
+			6
+	"""
+	root = newNode(1)
+	root.left = newNode(2)
+	root.right = newNode(3)
+	root.left.right = newNode(4)
+	root.left.right.right = newNode(5)
+	root.left.right.right.right = newNode(6)
+	print("Following are nodes in top",
+		"view of Binary Tree")
+	topview(root)
+
