python实现stack(栈)和队列(queue)

谁借莪１个温暖的怀抱￠ 2022-02-26 09:42 287阅读 0赞

栈是`先进后出` 队列`先进先出`  
栈示意图(顺便治治颈椎)：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MDY3ODIx_size_16_color_FFFFFF_t_70]  
队列示意图：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MDY3ODIx_size_16_color_FFFFFF_t_70 1]  
栈实现代码：

class Stack(object):
        def __init__(self):
            self.stack = []
    
        def push(self, v):
            self.stack.append(v)
    
        def pop(self):
            if self.stack:
                # 推出栈
                return self.stack.pop()
            else:
                raise LookupError("stack is empty")
    
        def is_empty(self):
            return bool(self.stack)
    
        def top(self):
            return self.stack[-1]

队列实现代码：

class Head(object):
        def __init__(self):
            self.right = None
            self.left = None
    
    
    class Node(object):
        def __init__(self, value):
            self.value = value
            self.next = None
    
    
    class Queue(object):
        def __init__(self):
            self.head = Head()
    
        def queue(self, value):
            new_node = Node(value)
            head = self.head
            if head.right:
                tmp = head.right
                head.right = new_node
                tmp.next = new_node
            else:
                head.left = head.right = new_node
    
        def dequeue(self):
            if self.is_empty():
                raise LookupError('Queue is empty')
            head = self.head
            tmp = head.left
            if head.left == head.right:
                head.left = head.right = None
            else:
                head.left = tmp.next
            return tmp.value
    
        def is_empty(self):
            return not bool(self.head.left)
    
        def top(self):
            if self.is_empty():
                raise LookupError('Queue is empty')
            return self.head.left.value

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![在这里插入图片描述][20190703100512270.jpg]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MDY3ODIx_size_16_color_FFFFFF_t_70]: /images/20220226/66079739251b4d9db1261118cce9d23b.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MDY3ODIx_size_16_color_FFFFFF_t_70 1]: /images/20220226/6b8d563a560d4040a5e508ffbac7dc91.png
[20190703100512270.jpg]: https://img-blog.csdnimg.cn/20190703100512270.jpg