Queue (隊列),俗稱FIFO結構,主要操作有兩個,enqueue(入隊)和dequeue(出隊),數組實現還有一個succ(迴繞)操作。
圖裏只畫了鏈表結構的enqueue和dequeue,還有線性結構的succ。
代碼只做了線性結構的,其他自己補完吧。
:)
#! /usr/bin/env python3
# coding:utf-8
class QueueException(Exception): pass
class QueueOverFlow(QueueException): pass
class QueueUnderFlow(QueueException): pass
class Queue:
def __init__(self, max_size):
self.max_size = max_size
self.data = [None] * max_size
self.size = 0
self.front = 0
self.rear = 0
def is_empty(self):
return self.size == 0
def is_full(self):
return self.size == self.max_size
def succ(self, current_index):
return (current_index + 1) % self.max_size
def enqueue(self, data):
if self.is_full():
raise QueueOverFlow
self.data[self.rear] = data
self.rear = self.succ(self.rear)
self.size += 1
def dequeue(self):
if self.is_empty():
raise QueueUnderFlow
data = self.data[self.front]
self.front = self.succ(self.front)
self.size -= 1
return data