python 实现线性链表(单链表)

发布时间:2019-07-23 09:42:56编辑:auto阅读(1303)

    初学python,拿数据结构中的线性链表存储结构练练手,理论比较简单,直接上代码。

    #!/usr/bin/python
    # -*- coding:utf-8 -*-
    
    # Author: Hui
    # Date:   2017-10-13
    
    # 结点类,
    class Node:
    
        def __init__(self, data):
            self.data = data            # 数据域
            self.next = None            # 指针域
    
        def get_data(self):
            return self.data
    
    
    # 链表类
    class List:
    
        def __init__(self, head):
            self.head = head            # 默认初始化头结点
    
        def is_empty(self):         # 空链表判断
            return self.get_len() == 0
    
        def get_len(self):          # 返回链表长度
            length = 0
            temp = self.head
            while temp is not None:
                length += 1
                temp = temp.next
            return length
    
        def append(self, node):         # 追加结点(链表尾部追加)
            temp = self.head
            while temp.next is not None:
                temp = temp.next
            temp.next = node
    
        def delete(self, index):           # 删除结点
            if index < 1 or index > self.get_len():
                print "给定位置不合理"
                return
            if index == 1:
                self.head = self.head.next
                return
            temp = self.head
            cur_pos = 0
            while temp is not None:
                cur_pos += 1
                if cur_pos == index-1:
                    temp.next = temp.next.next
                temp = temp.next
    
        def insert(self, pos, node):         # 插入结点
            if pos < 1 or pos > self.get_len():
                print "插入结点位置不合理..."
                return
            temp = self.head
            cur_pos = 0
            while temp is not Node:
                cur_pos += 1
                if cur_pos == pos-1:
                    node.next = temp.next
                    temp.next =node
                    break
                temp = temp.next
    
        def reverse(self, head):          # 反转链表
            if head is None and head.next is None:
                return head
            pre = head
            cur = head.next
            while cur is not None:
                temp = cur.next
                cur.next = pre
                pre = cur
                cur = temp
            head.next = None
            return pre
    
        def print_list(self, head):           # 打印链表
            init_data = []
            while head is not None:
                init_data.append(head.get_data())
                head = head.next
            return init_data
    
    
    if __name__ == '__main__':
    
        head = Node("head")
        list = List(head)
        print '初始化头结点:\t', list.print_list(head)
    
        for i in range(1, 10):
            node = Node(i)
            list.append(node)
        print '链表添加元素:\t', list.print_list(head)
    
        print '链表是否空:\t', list.is_empty()
    
        print '链表长度:\t', list.get_len()
    
        list.delete(9)
        print '删除第9个元素:\t',list.print_list(head)
    
        node = Node("insert")
        list.insert(3, node)
        print '第3个位置插入‘insert’字符串 :\t', list.print_list(head)
    
        head = list.reverse(head)
        print '链表反转:', list.print_list(head)
    
    执行结果:


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