diff --git a/Trees/BinarySearchTree.py b/Trees/BinarySearchTree.py
index 2b6333a..ea0e15a 100644
--- a/Trees/BinarySearchTree.py
+++ b/Trees/BinarySearchTree.py
@@ -44,23 +44,45 @@ def minValueNode(self, node):
 
         return current
 
-    def delete(self, data):
+    def maxValueNode(self, node):
+        current = node
+
+        # loop down to find the leftmost leaf
+        while(current.rightChild is not None):
+            current = current.rightChild
+
+        return current
+
+
+    def delete(self, data,root):
         ''' For deleting the node '''
         if self is None:
             return None
 
         # if current node's data is less than that of root node, then only search in left subtree else right subtree
         if data < self.data:
-            self.leftChild = self.leftChild.delete(data)
+            self.leftChild = self.leftChild.delete(data,root)
         elif data > self.data:
-            self.rightChild = self.rightChild.delete(data)
+            self.rightChild = self.rightChild.delete(data,root)
         else:
             # deleting node with one child
             if self.leftChild is None:
+
+                if self == root:
+                    temp = self.minValueNode(self.rightChild)
+                    self.data = temp.data
+                    self.rightChild = self.rightChild.delete(temp.data,root) 
+
                 temp = self.rightChild
                 self = None
                 return temp
             elif self.rightChild is None:
+
+                if self == root:
+                    temp = self.maxValueNode(self.leftChild)
+                    self.data = temp.data
+                    self.leftChild = self.leftChild.delete(temp.data,root) 
+
                 temp = self.leftChild
                 self = None
                 return temp
@@ -69,7 +91,7 @@ def delete(self, data):
             # first get the inorder successor
             temp = self.minValueNode(self.rightChild)
             self.data = temp.data
-            self.rightChild = self.rightChild.delete(temp.data)
+            self.rightChild = self.rightChild.delete(temp.data,root)
 
         return self
 
@@ -128,7 +150,7 @@ def insert(self, data):
 
     def delete(self, data):
         if self.root is not None:
-            return self.root.delete(data)
+            return self.root.delete(data,self.root)
 
     def find(self, data):
         if self.root:
@@ -189,4 +211,4 @@ def postorder(self):
     print('\n\nAfter deleting 10')
     tree.delete(10)
     tree.inorder()
-    tree.preorder()
+    tree.preorder()
\ No newline at end of file
diff --git a/Trees/zigzagtraversal_iterative.py b/Trees/zigzagtraversal_iterative.py
new file mode 100644
index 0000000..fa485b3
--- /dev/null
+++ b/Trees/zigzagtraversal_iterative.py
@@ -0,0 +1,75 @@
+class Node:
+    """
+    A Node has data variable and pointers to its left and right nodes.
+    """
+
+    def __init__(self, data):
+        self.left = None
+        self.right = None
+        self.data = data
+
+def make_tree() -> Node:
+    root = Node(1)
+    root.left = Node(2)
+    root.right = Node(3)
+    root.left.left = Node(4)
+    root.left.right = Node(5)
+    return root
+
+def zigzag_iterative(root: Node):
+    """
+    ZigZag traverse by iterative method: Print node left to right and right to left, alternatively.
+    """
+    if root == None: 
+        return 
+  
+    # two stacks to store alternate levels  
+    s1 = [] # For levels to be printed from right to left  
+    s2 = [] # For levels to be printed from left to right  
+  
+    # append first level to first stack 's1'  
+    s1.append(root)  
+  
+    # Keep printing while any of the stacks has some nodes  
+    while not len(s1) == 0 or not len(s2) == 0: 
+          
+        # Print nodes of current level from s1 and append nodes of next level to s2  
+        while not len(s1) == 0: 
+            temp = s1[-1]  
+            s1.pop()  
+            print(temp.data, end = " ")  
+  
+            # Note that is left is appended before right    
+            if temp.left: 
+                s2.append(temp.left)
+            if temp.right:  
+                s2.append(temp.right)
+  
+        # Print nodes of current level from s2 and append nodes of next level to s1  
+        while not len(s2) == 0: 
+            temp = s2[-1]  
+            s2.pop()  
+            print(temp.data, end = " ")  
+  
+            # Note that is rightt is appended before left   
+            if temp.right:  
+                s1.append(temp.right)
+            if temp.left: 
+                s1.append(temp.left)  
+
+def main():  # Main function for testing.
+    """
+    Create binary tree.
+    """
+    root = make_tree()
+    print("\nZigzag order traversal(iterative) is: ")
+    zigzag_iterative(root)
+    print()
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()
+    main()
+