remove duplicate nodes, singly linked list

Author: nickolasteixeira

Python/chapter02/2.1 - Remove Dups/Nick.py

@@ -0,0 +1,111 @@
+#!/usr/bin/python3
+import unittest
+
+
+class Node:
+    def __init__(self, data, next=None):
+        self.data = data
+        self.next = next
+
+    def __str__(self):
+        return str(self.data)
+
+
+class SinglyLinkedList:
+
+    def __init__(self):
+        self.head = None
+        self.size = 0
+
+    def insertHead(self, data):
+        print('Inserting head!----->', data)
+        n = Node(data)
+        temp = self.head
+        self.head = n
+        self.head.next = temp
+
+    def addNode(self, data):
+        if not self.head:
+            n = Node(data)
+            self.head = n
+        else:
+            n = self.head
+            while (n.next):
+                n = n.next
+
+            print('New Node added ---->', data)
+            new_node = Node(data)
+            n.next = new_node
+
+    def removeDuplicates(self):
+        print('Removing Duplicates.')
+        temp = self.head
+        nums = set()
+        while temp.next:
+            nums.add(temp.data)
+            if temp.next.data in nums:
+                temp.next = temp.next.next
+            temp = temp.next
+        print('Duplicates Removed!---------')
+
+    def removeDuplicatesNoBuffer(self):
+        print('Removing Duplicates - No buffer')
+        temp = self.head
+        while temp.next:
+            second = temp
+            while second.next:
+                if second.data == second.next.data:
+                    second.next = second.next.next
+                second = second.next
+            temp = temp.next
+        print('Duplicates Removed!----------')
+
+    def printList(self):
+        n = self.head
+
+        print('Printing Singly Linked List')
+        while(n):
+            print(n)
+            n = n.next
+
+
+class Test(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        cls.link = SinglyLinkedList()
+        cls.link.addNode(-1)
+        cls.link.addNode(-1)
+        cls.link.addNode(4)
+        cls.link.addNode(3)
+        cls.link.addNode(4)
+        cls.link.addNode(1)
+        cls.link.addNode(20)
+        cls.link.addNode(4)
+        cls.link.addNode(4)
+
+    @classmethod
+    def tearDownClass(cls):
+        print('---Teardown successful---')
+
+    def test1(self):
+        self.link.printList()
+
+    def test2(self):
+        self.link.removeDuplicates()
+        self.link.printList()
+
+    def test3(self):
+        self.link.addNode(-1)
+        self.link.addNode(20)
+        self.link.addNode(40)
+        self.link.printList()
+        self.link.removeDuplicatesNoBuffer()
+        self.link.printList()
+
+    def test4(self):
+        self.link.insertHead(-2)
+        self.link.printList()
+
+
+if __name__ == "__main__":
+    unittest.main()