Three Hundred - Eight Commit: Implement LinkedList class

Author: AAdewunmi

Section_11(Hash-Table)/linkedlist.py

@@ -0,0 +1,120 @@
+# Node Class
+# ==========
+class _Node(object):
+ __slots__ = '_element', '_next'
+
+ # Constructor
+ def __init__(self, element, next):
+ self._element = element
+ self._next = next
+
+
+# Linked List Class
+# ===========
+class LinkedList:
+ # Constructor
+ def __init__(self):
+ self._head = None
+ self._tail = None
+ self._size = 0
+
+ # Find length of the Linked List
+ def __len__(self):
+ return self._size
+
+ # Check whether Linked List is empty
+ def is_empty(self):
+ return self._size == 0
+
+ # Add Nodes to the back of the Linked List
+ def add_last(self, e):
+ newest = _Node(e, None)
+ if self.is_empty():
+ self._head = newest
+ else:
+ self._tail._next = newest
+ self._tail = newest
+ self._size += 1
+
+ # Traverse the Linked List and display elements
+ def display(self):
+ p = self._head
+ while p:
+ print(p._element, end=' --> ')
+ p = p._next
+ print()
+
+ # Search for an element in a Linked List
+ def search(self, key):
+ p = self._head
+ index = 0
+ while p:
+ if p._element == key:
+ return index
+ p = p._next
+ index += 1
+ return -1
+
+ # Add Nodes to the front of the Linked List
+ def add_first(self, key):
+ newest = _Node(key, None)
+ if self.is_empty():
+ self._head = newest
+ self._tail = newest
+ else:
+ newest._next = self._head
+ self._head = newest
+ self._size += 1
+
+ # Add Nodes to any position in a Linked List
+ def add_any(self, key, position):
+ newest = _Node(key, 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
+
+ # Remove an element from the beginning of a Linked List
+ def remove_first(self):
+ if self.is_empty():
+ print('List is empty')
+ return
+ e = self._head._element
+ self._head = self._head._next
+ self._size -= 1
+ if self.is_empty():
+ self._tail = None
+ return e
+
+ # Remove an element from the end of a Linked List
+ def remove_last(self):
+ if self.is_empty():
+ 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
+
+ # Remove an element at any position in a Linked List
+ def remove_any(self, position):
+ p = self._head
+ i = 1
+ while i < position - 1:
+ p = p._next
+ i = i + 1
+ e = p._next._element
+ p._next = p._next._next
+ self._size -= 1
+ return e