1 2 3 4 5 6 | def delete_first(self): deleted = self.head if self.head: self.head = self.head.next deleted.next = None return deleted |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | class Element(object): def __init__(self, value): self.value = value self.next = None class LinkedList(object): def __init__(self, head=None): self.head = head def append(self, new_element): current = self.head if self.head: while current.next: current = current.next current.next = new_element else: self.head = new_element def insert_first(self, new_element): new_element.next = self.head self.head = new_element def delete_first(self): if self.head: deleted_element = self.head temp = deleted_element.next self.head = temp return deleted_element else: return Noneclass Stack(object): def __init__(self,top=None): self.ll = LinkedList(top) def push(self, new_element): self.ll.insert_first(new_element) def pop(self): return self.ll.delete_first() |
