Linked List

Author: codehariom

linked list/LLRemoveLastElement.py

@@ -0,0 +1,105 @@
+class _Node:
+    __slots__ = '_element', '_next'
+
+    def __init__(self, element, next):
+        self._element = element
+        self._next = next
+
+class LinkedList:
+    def __init__(self):
+        self._head = None
+        self._tail = None
+        self._size = 0
+
+    def __len__(self):
+        return self._size
+
+    def isempty(self):
+        return self._size == 0
+
+    def addlast(self, e):
+        newest = _Node(e, None)
+        if self.isempty():
+            self._head = newest
+        else:
+            self._tail._next = newest
+        self._tail = newest
+        self._size += 1
+
+    def addfirst(self, e):
+        newest = _Node(e, None)
+        if self.isempty():
+            self._head = newest
+            self._tail = newest
+        else:
+            newest._next = self._head
+            self._head = newest
+        self._size += 1
+
+    def addany(self, e, position):
+        newest = _Node(e, None)
+        p = self._head
+        i = 1
+        while i < position-1:
+            p = p._next
+            i = i + 1
+        newest._next = p._next
+        p._next = newest
+        self._size += 1
+
+    def removefirst(self):
+        if self.isempty():
+            print('List is empty')
+            return
+        e = self._head._element
+        self._head = self._head._next
+        self._size -= 1
+        if self.isempty():
+            self._tail = None
+        return e
+
+    def removelast(self):
+        if self.isempty():
+            print('List is empty')
+            return
+        p = self._head
+        i = 1
+        while i < len(self) - 1:
+            p = p._next
+            i = i + 1
+        self._tail = p
+        p = p._next
+        e = p._element
+        self._tail._next = None
+        self._size -= 1
+        return e
+
+    def display(self):
+        p = self._head
+        while p:
+            print(p._element,end='-->')
+            p = p._next
+        print()
+
+    def search(self,key):
+        p = self._head
+        index = 0
+        while p:
+            if p._element == key:
+                return index
+            p = p._next
+            index = index + 1
+        return -1
+
+L = LinkedList()
+L.addlast(7)
+L.addlast(4)
+L.addlast(12)
+L.addlast(8)
+L.addlast(3)
+L.display()
+print('Size:',len(L))
+ele = L.removelast()
+L.display()
+print('Size:',len(L))
+print('Element Removed',ele)