You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
100 lines
2.6 KiB
100 lines
2.6 KiB
"""
|
|
File: array_queue.py
|
|
Created Time: 2022-12-01
|
|
Author: Peng Chen (pengchzn@gmail.com)
|
|
"""
|
|
|
|
import os.path as osp
|
|
import sys
|
|
|
|
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
|
|
from include import *
|
|
|
|
""" 基于环形数组实现的队列 """
|
|
class ArrayQueue:
|
|
def __init__(self, size):
|
|
self.__nums = [0] * size # 用于存储队列元素的数组
|
|
self.__front = 0 # 队首指针，指向队首元素
|
|
self.__size = 0 # 队列长度
|
|
|
|
""" 获取队列的容量 """
|
|
def capacity(self):
|
|
return len(self.__nums)
|
|
|
|
""" 获取队列的长度 """
|
|
def size(self):
|
|
return self.__size
|
|
|
|
""" 判断队列是否为空 """
|
|
def is_empty(self):
|
|
return self.__size == 0
|
|
|
|
""" 入队 """
|
|
def push(self, num):
|
|
assert self.__size < self.capacity(), "队列已满"
|
|
# 计算尾指针，指向队尾索引 + 1
|
|
# 通过取余操作，实现 rear 越过数组尾部后回到头部
|
|
rear = (self.__front + self.__size) % self.capacity()
|
|
# 尾结点后添加 num
|
|
self.__nums[rear] = num
|
|
self.__size += 1
|
|
|
|
""" 出队 """
|
|
def poll(self):
|
|
num = self.peek()
|
|
# 队首指针向后移动一位，若越过尾部则返回到数组头部
|
|
self.__front = (self.__front + 1) % self.capacity()
|
|
self.__size -= 1
|
|
return num
|
|
|
|
""" 访问队首元素 """
|
|
def peek(self):
|
|
assert not self.is_empty(), "队列为空"
|
|
return self.__nums[self.__front]
|
|
|
|
""" 返回列表用于打印 """
|
|
def to_list(self):
|
|
res = [0] * self.size()
|
|
j = self.__front
|
|
for i in range(self.size()):
|
|
res[i] = self.__nums[(j % self.capacity())]
|
|
j += 1
|
|
return res
|
|
|
|
|
|
""" Driver Code """
|
|
if __name__ == "__main__":
|
|
""" 初始化队列 """
|
|
queue = ArrayQueue(10)
|
|
|
|
""" 元素入队 """
|
|
queue.push(1)
|
|
queue.push(3)
|
|
queue.push(2)
|
|
queue.push(5)
|
|
queue.push(4)
|
|
print("队列 queue =", queue.to_list())
|
|
|
|
""" 访问队首元素 """
|
|
peek = queue.peek()
|
|
print("队首元素 peek =", peek)
|
|
|
|
""" 元素出队 """
|
|
poll = queue.poll()
|
|
print("出队元素 poll =", poll)
|
|
print("出队后 queue =", queue.to_list())
|
|
|
|
""" 获取队列的长度 """
|
|
size = queue.size()
|
|
print("队列长度 size =", size)
|
|
|
|
""" 判断队列是否为空 """
|
|
is_empty = queue.is_empty()
|
|
print("队列是否为空 =", is_empty)
|
|
|
|
""" 测试环形数组 """
|
|
for i in range(10):
|
|
queue.push(i);
|
|
queue.poll();
|
|
print("第", i, "轮入队 + 出队后 queue = ", queue.to_list());
|