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Add python code for queue

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This commit is contained in:
pengchzn 2022-12-01 06:53:08 +08:00
parent a2b7586c98
commit 59e46ada82
3 changed files with 45 additions and 28 deletions
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53
codes/python/chapter_stack_and_queue/array_queue.py
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@ -1,6 +1,6 @@
''' '''
File: array_queue.py File: array_queue.py
Created Time: 2022-11-29 Created Time: 2022-12-01
Author: Peng Chen (pengchzn@gmail.com) Author: Peng Chen (pengchzn@gmail.com)
''' '''
@ -13,22 +13,22 @@ from include import *
""" 基于环形数组实现的队列 """ """ 基于环形数组实现的队列 """
class ArrayQueue: class ArrayQueue:
def __init__(self, size): def __init__(self, size):
self.nums = [None] * size # 用于存储队列元素的数组 self.__nums = [None] * size # 用于存储队列元素的数组
self.front = 0 # 头指针，指向队首 self.__front = 0 # 头指针，指向队首
self.rear = 0 # 尾指针，指向队尾 + 1 self.__rear = 0 # 尾指针，指向队尾 + 1
""" 获取队列的容量 """ """ 获取队列的容量 """
def capacity(self): def capacity(self):
return len(self.nums) return len(self.__nums)
""" 获取队列的长度 """ """ 获取队列的长度 """
def size(self): def size(self):
# 由于将数组看作为环形，可能 rear < front ，因此需要取余数 # 由于将数组看作为环形，可能 rear < front ，因此需要取余数
return (self.capacity() + self.rear - self.front) % self.capacity() return (self.capacity() + self.__rear - self.__front) % self.capacity()
""" 判断队列是否为空 """ """ 判断队列是否为空 """
def is_empty(self): def is_empty(self):
return len(self.nums)==0 return (self.__rear - self.__front) == 0
""" 入队 """ """ 入队 """
def put(self, val): def put(self, val):
@ -36,9 +36,9 @@ class ArrayQueue:
print("队列已满") print("队列已满")
return False return False
# 尾结点后添加 num # 尾结点后添加 num
self.nums[self.rear] = val self.__nums[self.__rear] = val
# 尾指针向后移动一位，越过尾部后返回到数组头部 # 尾指针向后移动一位，越过尾部后返回到数组头部
self.rear = (self.rear + 1) % self.capacity() self.__rear = (self.__rear + 1) % self.capacity()
""" 出队 """ """ 出队 """
def get(self): def get(self):
@ -46,28 +46,39 @@ class ArrayQueue:
if self.is_empty(): if self.is_empty():
print("队列为空") print("队列为空")
return False return False
num = self.nums[self.front] num = self.__nums[self.__front]
self.nums[self.front] = None
# 队头指针向后移动，越过尾部后返回到数组头部 # 队头指针向后移动，越过尾部后返回到数组头部
self.front = (self.front + 1) % self.capacity() self.__front = (self.__front + 1) % self.capacity()
return num return num
""" 访问队首元素 """ """ 访问队首元素 """
def peek(self): def peek(self):
# 删除头结点 # 删除头结点
if self.is_empty(): if self.is_empty():
return 1 print("队列为空")
return self.nums[self.front] return False
return self.__nums[self.__front]
""" 访问指定位置元素 """ """ 访问指定位置元素 """
def get_index(self, index): def get_index(self, index):
if index >= self.size(): if index >= self.size():
return -1 print("索引越界")
return self.nums[(self.front + index) % self.capacity()] return False
return self.__nums[(self.__front + index) % self.capacity()]
""" 返回列表用于打印 """
def to_list(self):
res = [None] * self.size()
j = self.__front
for i in range(self.size()):
res[i] = self.__nums[(j % self.capacity())]
j += 1
return res
if __name__ == "__main__": if __name__ == "__main__":
""" 初始化队列 """ """ 初始化队列 """
queue = ArrayQueue(5) queue = ArrayQueue(10)
""" 元素入队 """ """ 元素入队 """
queue.put(1) queue.put(1)
@ -75,16 +86,20 @@ if __name__ == "__main__":
queue.put(2) queue.put(2)
queue.put(5) queue.put(5)
queue.put(4) queue.put(4)
print("队列 queue = ", queue.nums) print("队列 queue = ", queue.to_list())
""" 访问队首元素 """ """ 访问队首元素 """
peek = queue.peek() peek = queue.peek()
print("队首元素 peek = ", peek) print("队首元素 peek = ", peek)
""" 访问索引 index 处元素 """
num = queue.get_index(3)
print("队列索引 3 处的元素为 num =", num)
""" 元素出队 """ """ 元素出队 """
get = queue.get() get = queue.get()
print("出队元素 get = ", get) print("出队元素 get = ", get)
print("出队后 queue = ", queue.nums) print("出队后 queue = ", queue.to_list())
""" 获取队列的长度 """ """ 获取队列的长度 """
size = queue.size() size = queue.size()

8
codes/python/chapter_stack_and_queue/deque.py
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@ -38,10 +38,10 @@ if __name__ == "__main__":
print("队尾出队元素 popLast= ", popLast) print("队尾出队元素 popLast= ", popLast)
print("队尾出队后 duque = ", duque) print("队尾出队后 duque = ", duque)
""" 获取队列的长度 """ """ 获取双向队列的长度 """
size = len(duque) size = len(duque)
print("队列长度 size = ", size) print("双向队列长度 size = ", size)
""" 判断队列是否为空 """ """ 判断双向队列是否为空 """
is_empty = len(duque) == 0 is_empty = len(duque) == 0
print("队列是否为空 = ", is_empty) print("双向队列是否为空 = ", is_empty)

12
codes/python/chapter_stack_and_queue/linkedlist_queue.py
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@ -1,6 +1,6 @@
''' '''
File: linkedlist_queue.py File: linkedlist_queue.py
Created Time: 2022-11-29 Created Time: 2022-12-01
Author: Peng Chen (pengchzn@gmail.com) Author: Peng Chen (pengchzn@gmail.com)
''' '''
@ -50,10 +50,12 @@ class LinkedListQueue:
""" 访问队首元素 """ """ 访问队首元素 """
def peek(self): def peek(self):
if self.size() == 0: if self.size() == 0:
return -1 print("队列为空")
return False
return self.__front.val return self.__front.val
def to_array(self): """ 转化为列表用于打印 """
def to_list(self):
queue = [] queue = []
temp = self.__front temp = self.__front
while temp: while temp:
@ -72,7 +74,7 @@ if __name__ == "__main__":
queue.put(2) queue.put(2)
queue.put(5) queue.put(5)
queue.put(4) queue.put(4)
print("队列 queue = ", queue.to_array()) print("队列 queue = ", queue.to_list())
""" 访问队首元素 """ """ 访问队首元素 """
peek = queue.peek() peek = queue.peek()
@ -81,7 +83,7 @@ if __name__ == "__main__":
""" 元素出队 """ """ 元素出队 """
get = queue.get() get = queue.get()
print("出队元素 get = ", get) print("出队元素 get = ", get)
print("出队后 queue = ", queue.to_array()) print("出队后 queue = ", queue.to_list())
""" 获取队列的长度 """ """ 获取队列的长度 """
size = queue.size() size = queue.size()