diff --git a/Sprint-2/implement_linked_list/linked_list.py b/Sprint-2/implement_linked_list/linked_list.py index e69de29b..92a32fc2 100644 --- a/Sprint-2/implement_linked_list/linked_list.py +++ b/Sprint-2/implement_linked_list/linked_list.py @@ -0,0 +1,56 @@ +class LinkedList: + class Node: + __slots__ = ("next","previous","value") + + def __init__(self, value): + self.next = None + self.previous = None + self.value = value + + def __init__(self): + self.head = None + self.tail = None + self.size = 0 + + def push_head(self, value): + new_node = self.Node(value=value) + if self.head == None: + self.head = new_node + self.tail = new_node + else: + new_node.next = self.head + self.head.previous = new_node + self.head = new_node + self.size += 1 + return new_node + + def pop_tail(self): + if self.tail == None: + return + removed_value = self.tail.value + + self.remove(self.tail) + return removed_value + + + def remove(self, node): + if node == None: + return + if node == self.head and node == self.tail: + self.head = None + self.tail = None + + elif node == self.head: + self.head = self.head.next + self.head.previous = None + + elif node == self.tail: + self.tail = self.tail.previous + self.tail.next = None + + else: + node.next.previous = node.previous + node.previous.next = node.next + node.next = None + node.previous = None + self.size -= 1