Create deleteNode.py

src/chapter03linkedlists/deleteNode.py

@@ -0,0 +1,71 @@
+class Node: 
+
+    # Constructor to initialize the node object 
+    def __init__(self, data): 
+        self.data = data 
+        self.next = None
+
+class LinkedList: 
+
+    # Function to initialize head 
+    def __init__(self): 
+        self.head = None
+
+    # Function to insert a new node at the beginning 
+    def push(self, new_data): 
+        new_node = Node(new_data) 
+        new_node.next = self.head 
+        self.head = new_node 
+
+    # Given a reference to the head of a list and a key, 
+    # delete the first occurence of key in linked list 
+    def deleteNode(self, key): 
+
+        # Store head node 
+        temp = self.head 
+
+        # If head node itself holds the key to be deleted 
+        if (temp is not None): 
+            if (temp.data == key): 
+                self.head = temp.next
+                temp = None
+                return
+
+        # Search for the key to be deleted, keep track of the 
+        # previous node as we need to change 'prev.next' 
+        while(temp is not None): 
+            if temp.data == key: 
+                break 
+            prev = temp 
+            temp = temp.next 
+
+        # if key was not present in linked list 
+        if(temp == None): 
+            return 
+
+        # Unlink the node from linked list 
+        prev.next = temp.next 
+
+        temp = None 
+
+
+    # Utility function to print the linked LinkedList 
+    def printList(self): 
+        temp = self.head 
+        while(temp): 
+            print " %d" %(temp.data), 
+            temp = temp.next
+
+
+# Driver program 
+llist = LinkedList() 
+llist.push(7) 
+llist.push(1) 
+llist.push(3) 
+llist.push(2) 
+
+print "Created Linked List: "
+llist.printList() 
+llist.deleteNode(1)  
+print "\nLinked List after Deletion of 1:"
+llist.printList()