# 单链表
# 结点 class Node: def __init__(self, data, next_node): self.data = data self.next_node = next_node # 创建链表 class LinkedList: def __init__(self, first_node): self.first_node = first_node
# 按索引读取 def link_read(self, read_index): # 从第一个结点开始 current_node = self.first_node current_index = 0 while current_index < read_index: # 当前索引小于要找的索引,就需要继续顺着链往下找,直至找到我们要找的索引值 current_node = current_node.next_node current_index += 1 # 如果读到最后一个结点之后,就说明所找的索引不在链表中,因此返回None if not current_node: return None return current_node.data
# 查找值的索引 def link_search(self, search_value): # 从第一个结点开始 current_node = self.first_node current_index = 0 while current_node.data != search_value: # 如果当前结点的值不是要找的值,就需要继续顺着链往下找,直至找到我们要找的值 current_node = current_node.next_node current_index += 1 # 如果读到最后一个结点之后,就说明所找的值不在链表中,因此返回None if not current_node: return None return current_index
# 插入 def link_insert(self, new_data, insert_at_index): # 创建插入的新结点 new_node = Node(new_data, None) # 如果在开头插入, 则将新结点指向原first_node # 并重新设置first_node if insert_at_index == 0: new_node.next_node = node_01 self.first_node = new_node return "insert at start successfully" # 找到新结点插入位置前的那一个结点 current_node = self.first_node current_index = 0 prevent_index = insert_at_index - 1 while current_index < prevent_index: temporary_node = current_node # 当前索引小于要找的索引前一个,就需要继续顺着链往下找,直至找到我们要找的索引值 current_node = current_node.next_node current_index += 1 # 如果要添加的结点超过链表最大索引就插入链表最末尾 if not current_node: current_node = temporary_node break # 当前结点下一个结点是新结点,新结点的下一个结点是当前结点的下一结点 new_node.next_node = current_node.next_node current_node.next_node = new_node return "insert successfully"
# 删除 def link_delete(self, delete_at_index): # 如果删除的结点是第一个,则只需将first_node重置为第二个结点便可 if delete_at_index == 0: self.first_node = node_02 return node_01.data # 如果删除的结点不是第一个,需要找到要删结点的前一个结点 current_node = self.first_node current_index = 0 prevent_index = delete_at_index - 1 while current_index < prevent_index: temporary_node = current_node current_node = current_node.next_node current_index += 1 # 如果要删除的结点超过链表最大索引就删除链表最末尾的结点 if not current_node.next_node: temporary_node.next_node = None return temporary_node.data # 要删除的结点和要删除结点的后一个结点 delete_node = current_node.next_node after_delete_node = delete_node.next_node # 将要删除结点的前一个结点的next_node指向要删除结点的后一个结点 current_node.next_node = after_delete_node delete_node.next_node = None return delete_node.data if __name__ == '__main__': node_09 = Node("plus", None) node_08 = Node("flay", node_09) node_07 = Node("dump", node_08) node_06 = Node("blog", node_07) node_05 = Node("load", node_06) node_04 = Node("lope", node_05) node_03 = Node("amid", node_04) node_02 = Node("upon", node_03) node_01 = Node("once", node_02) # 将第一个结点node_01作为指针创建链表 link_list = LinkedList(node_01) print(link_list.link_read(5)) print(link_list.link_search("dump")) print(link_list.link_insert("jeep", 12)) print(link_list.link_delete(13))
# 双链表
# 结点 class Node: def __init__(self, data): self.data = data self.previous_node = None self.next_node = None # 创建双链表 class DoublyLinkedList: def __init__(self, first_node, last_node): self.first_node = first_node self.last_node = last_node # 在链表末尾插入数据 def insert_at_end(self, insert_value): # 创建新结点 new_node = Node(insert_value) # 如果链表还没有任何结点 if not self.first_node: self.first_node = new_node self.last_node = new_node else: # 否则,将新结点的prevent_node指向链表的原last_node new_node.previous_node = self.last_node # 将链表的原last_node的next_node指向新结点 self.last_node.next_node = new_node # 将链表的原last_node重新设置为新结点 self.last_node = new_node return new_node.data # 在链表开头删除数据 def remove_from_front(self): remove_node = self.first_node self.first_node = remove_node.next_node return remove_node.data # 基于双链表的队列 class LinkQueue: def __init__(self, first_node, last_node): self.link_queue = DoublyLinkedList(first_node, last_node) # 入队 def entry_queue(self, entry_value): self.link_queue.insert_at_end(entry_value) return str(entry_value) + "入队成功" # 出队 def leave_queue(self): remove_node = self.link_queue.remove_from_front() return str(remove_node) + "出队成功" # 查看队列末尾数据 def link_tail(self): tail_value = self.link_queue.last_node.data return tail_value if __name__ == '__main__': node_09 = Node("plus") node_08 = Node("flay") node_07 = Node("dump") node_06 = Node("blog") node_05 = Node("load") node_04 = Node("lope") node_03 = Node("amid") node_02 = Node("upon") node_01 = Node("once") node_01.next_node = node_02 node_02.previous_node = node_01 node_02.next_node = node_03 node_03.previous_node = node_02 node_03.next_node = node_04 node_04.previous_node = node_03 node_04.next_node = node_05 node_05.previous_node = node_04 node_05.next_node = node_06 node_06.previous_node = node_05 node_06.next_node = node_07 node_07.previous_node = node_06 node_07.next_node = node_08 node_08.previous_node = node_07 node_08.next_node = node_09 node_09.previous_node = node_08 # 将第一个结点node_01作为开始指针,将最后一个结点node_09作为结尾指针创建链表 doubly_link_list = DoublyLinkedList(node_01, node_09) print(doubly_link_list.insert_at_end("blue")) print(doubly_link_list.remove_from_front()) my_queue = LinkQueue(node_01, node_09) print(my_queue.entry_queue("lazy")) print(my_queue.leave_queue()) print(my_queue.link_tail())