Python-数组实现循环队列和非循环队列
什么是队列？
队列就是只能在一端插入，而在另一端删除的线性表，故队列又称为先进先出队列
队列类型有哪些？
循环队列和顺序队列
队列的存储实现方式有哪些？
顺序存储（数组）和链式存储（链表），此博文描述的是数组的实现（后续更新链表实现）
代码实现
初始化队列：初始化一个size长度的队列，队列的值都为0
判断队列是否已满：队列满，不可插入队列
判断队列是否为空：队列空，没有数据可以出队
入队：将数据item插入队列
出队：将对头元素从队列中删除并返回的值
class Queue:
"""非循环队列"""
def __init__(self, size):
self.size = size
self.front = -1
self.rear = -1
self.queue = [0]*size
def enqueue(self, item):
if self.isFull():
raise Exception('队列满')
else:
self.rear += 1
self.queue[self.rear] = item
def dequeue(self):
if self.isEmpty():
raise Exception('队列空')
else:
self.front += 1
data = self.queue[self.front]
self.queue[self.front] = 0
return data
def isFull(self):
return self.rear - self.front == self.size
def isEmpty(self):
return self.rear == self.front
def showQueue(self):
print(self.queue)
class circleQueue:
"""循环队列"""
def __init__(self, size):
self.size = size
self.front = 0
self.rear = 0
self.queue = [0]*size
def enQueue(self, item):
"""进队列，将值放进队列"""
if self.isFull():
raise Exception('队列满')
else:
self.rear = (self.rear+1) % self.size
self.queue[self.rear] = item
def deQueue(self):
"""出队列，并返回出队列的值"""
if self.isEmpty():
raise Exception('队列空')
else:
self.front = (self.front+1) % self.size
data = self.queue[self.front]
self.queue[self.front] = 0
return data
def isEmpty(self):
return self.rear == self.front
def isFull(self):
return (self.rear+1) % self.size == self.front
def showQueue(self):
print(self.queue)
if __name__ == '__main__':
queue = circleQueue(5)
#Testcase1：队列未插入任何值
print(queue.isEmpty()) #Expected:True
print(queue.isFull()) #Expected:False
# #Testcase2:队列空，出队列的值
# queue.deQueue() #Excepted:抛出队列空的异常
#Testcase3：队列未满,入队列和出队列
for i in range(1,4):
queue.enQueue(i)
queue.showQueue() #Expected:[0, 1, 2, 3, 0]
print(queue.isEmpty()) #Expected:False
print(queue.isFull()) #Expected:False
queue.deQueue()
queue.showQueue() #Expected:[0, 0, 2, 3, 0]
# #Testcase4:队列已满，继续插入
# for i in range(1,5):
# queue.enQueue(i)
# queue.enQueue(5) #Expected:抛出队列满的异常
作者：LeechengLove
