标签:ini span pytho current index one object main 头部
概念:什么是双向链表
双向链表也叫双链表,是链表的一种,它的每个数据结点中都有两个指针,分别指向直接后继和直接前驱。
所以,从双向链表中的任意一个结点开始,都可以很方便地访问它的前驱结点和后继结点。一般我们都构造双向循环链表。
代码简单实现:
""" author: zhao xian xin 不积跬步无以至千里 """ #定义双向链表 每一个结点 class Node(object): def __init__(self, item): self.previous = None self.item = item self.next = None # 定义链表 class TwoWayLinkList(): """ 链表基本属性 """ def __init__(self): self.hearder = None self.length = 0 """ 头部插入 """ def firstAdd(self, node): if self.hearder == None: self.hearder = node else: node.next = self.hearder self.hearder.previous = node self.hearder = node self.length += 1 """ 尾部插入 """ def tailAdd(self, node): if self.length == 0: self.firstAdd(node) else: currentNode = self.hearder for i in range(self.length - 1): currentNode = currentNode.next node.previous = currentNode currentNode.next = node self.length += 1 """ 根据指定索引 插入 对应结点 """ def indexInsert(self, index, node): assert index != 0 or index <= self.length, "超出索引" if index == 1: self.firstAdd(node) elif index == 2: node.next = self.hearder.next node.prevopus = self.hearder self.hearder.next = node self.length += 1 elif index > self.length: self.tailAdd(node) else: currentNode = self.hearder for i in range(1, index - 1): currentNode = currentNode.next node.prevopus = currentNode node.next = currentNode.next currentNode.next.previous = node currentNode.next = node self.length += 1 """ 根据指定位置 删除 结点""" def delNode(self, index): """ 判断删除的索引是否在标准范围之中 """ assert index != 0 or index <= self.length, "超出索引" if index == 1: self.hearder = self.hearder.next self.hearder.previous = None elif index == 2: self.hearder.next = self.hearder.next.next self.hearder.next.next.previous = self.hearder else: currentNode = self.hearder for i in range(1, index - 1): currentNode = currentNode.next currentNode.next = currentNode.next.next self.length -= 1 """ 遍历节点""" def rangeNode(self): assert self.length != 0 , "链表为空" currentNode = self.hearder for i in range(self.length): element = currentNode.item currentNode = currentNode.next print(element, end=" ") """ 结点之间的排序 不许改变指针位置, 只需改变链表中元素位置 """ def sortNode(self): pass """ 快速排序 """ for i in range(self.length): currentNode = self.hearder for j in range(0, self.length - i - 1): if currentNode.item > currentNode.next.item: mid = currentNode.item currentNode.item = currentNode.next.item currentNode.next.item = mid """ 别忘记 交换节点 """ currentNode = currentNode.next if __name__ == "__main__": node = Node(2) t = TwoWayLinkList() t.firstAdd(node) print(t.rangeNode()) """ 尾部 插入元素 """ t.tailAdd(Node(1)) t.tailAdd(Node(4)) print(t.rangeNode()) """ 头部插入位置 """ t.firstAdd(Node(3)) print(t.rangeNode()) """ 根据索引插入对应的位置 """ t.indexInsert(6, Node(5)) print(t.rangeNode()) """ 根据指定位置 删除节点 """ t.delNode(4) print(t.rangeNode()) """ 节点之间的 排序 """ t.sortNode() print("======排序======") print(t.rangeNode())
标签:ini span pytho current index one object main 头部
原文地址:https://www.cnblogs.com/zhaoxianxin/p/13612414.html