From a2b7586c986733f81c6549b9bff7c3fbb98dd267 Mon Sep 17 00:00:00 2001 From: pengchzn Date: Wed, 30 Nov 2022 12:15:50 +0800 Subject: [PATCH] Add python code for queue --- .../chapter_stack_and_queue/array_queue.py | 91 ++++++++++++++++++- codes/python/chapter_stack_and_queue/deque.py | 43 ++++++++- .../linkedlist_queue.py | 88 +++++++++++++++++- codes/python/chapter_stack_and_queue/queue.py | 38 +++++++- 4 files changed, 248 insertions(+), 12 deletions(-) diff --git a/codes/python/chapter_stack_and_queue/array_queue.py b/codes/python/chapter_stack_and_queue/array_queue.py index 7bc6a32..0e173fe 100644 --- a/codes/python/chapter_stack_and_queue/array_queue.py +++ b/codes/python/chapter_stack_and_queue/array_queue.py @@ -1,10 +1,95 @@ ''' File: array_queue.py -Created Time: 2022-11-25 -Author: Krahets (krahets@163.com) +Created Time: 2022-11-29 +Author: Peng Chen (pengchzn@gmail.com) ''' -import sys, os.path as osp +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 = [None] * size # 用于存储队列元素的数组 + self.front = 0 # 头指针，指向队首 + self.rear = 0 # 尾指针，指向队尾 + 1 + + """ 获取队列的容量 """ + def capacity(self): + return len(self.nums) + + """ 获取队列的长度 """ + def size(self): + # 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() + + """ 判断队列是否为空 """ + def is_empty(self): + return len(self.nums)==0 + + """ 入队 """ + def put(self, val): + if self.size() == self.capacity(): + print("队列已满") + return False + # 尾结点后添加 num + 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 + self.rear = (self.rear + 1) % self.capacity() + + """ 出队 """ + def get(self): + # 删除头结点 + if self.is_empty(): + print("队列为空") + return False + 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 + self.front = (self.front + 1) % self.capacity() + return num + + """ 访问队首元素 """ + def peek(self): + # 删除头结点 + if self.is_empty(): + return 1 + return self.nums[self.front] + + """ 访问指定位置元素 """ + def get_index(self, index): + if index >= self.size(): + return -1 + return self.nums[(self.front + index) % self.capacity()] + +if __name__ == "__main__": + """ 初始化队列 """ + queue = ArrayQueue(5) + + """ 元素入队 """ + queue.put(1) + queue.put(3) + queue.put(2) + queue.put(5) + queue.put(4) + print("队列 queue = ", queue.nums) + + """ 访问队首元素 """ + peek = queue.peek() + print("队首元素 peek = ", peek) + + """ 元素出队 """ + get = queue.get() + print("出队元素 get = ", get) + print("出队后 queue = ", queue.nums) + + """ 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) diff --git a/codes/python/chapter_stack_and_queue/deque.py b/codes/python/chapter_stack_and_queue/deque.py index 9894975..0bddd0d 100644 --- a/codes/python/chapter_stack_and_queue/deque.py +++ b/codes/python/chapter_stack_and_queue/deque.py @@ -1,10 +1,47 @@ ''' File: deque.py -Created Time: 2022-11-25 -Author: Krahets (krahets@163.com) +Created Time: 2022-11-29 +Author: Peng Chen (pengchzn@gmail.com) ''' -import sys, os.path as osp +import os.path as osp +import sys + sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__)))) from include import * +from collections import deque + +if __name__ == "__main__": + """ 初始化双向队列 """ + duque = deque() + + """ 元素入队 """ + duque.append(2) # 添加至队尾 + duque.append(5) + duque.append(4) + duque.appendleft(3) # 添加至队首 + duque.appendleft(1) + print("双向队列 duque = ", duque) + + """ 访问队首元素 """ + peekFirst = duque[0] # 队首元素 + print("队首元素 peekFirst = ", peekFirst) + peekLast = duque[-1] # 队尾元素 + print("队尾元素 peekLast = ", peekLast) + + """ 元素出队 """ + popFirst = duque.pop() # 队首元素出队 + print("队首出队元素 popFirst= ", popFirst) + print("队首出队后 duque = ", duque) + popLast = duque.popleft() # 队尾元素出队 + print("队尾出队元素 popLast= ", popLast) + print("队尾出队后 duque = ", duque) + + """ 获取队列的长度 """ + size = len(duque) + print("队列长度 size = ", size) + + """ 判断队列是否为空 """ + is_empty = len(duque) == 0 + print("队列是否为空 = ", is_empty) diff --git a/codes/python/chapter_stack_and_queue/linkedlist_queue.py b/codes/python/chapter_stack_and_queue/linkedlist_queue.py index 3606c8a..53f3b9a 100644 --- a/codes/python/chapter_stack_and_queue/linkedlist_queue.py +++ b/codes/python/chapter_stack_and_queue/linkedlist_queue.py @@ -1,10 +1,92 @@ ''' File: linkedlist_queue.py -Created Time: 2022-11-25 -Author: Krahets (krahets@163.com) +Created Time: 2022-11-29 +Author: Peng Chen (pengchzn@gmail.com) ''' -import sys, os.path as osp +import os.path as osp +import sys + sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__)))) from include import * +""" 基于链表实现的队列 """ +class LinkedListQueue: + def __init__(self): + self.__front = 0 # 头结点 front + self.__rear = 0 # 尾结点 rear + self.__size = 0 + + """ 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 not self.__front + + """ 入队 """ + def put(self, num): + # 尾结点后添加 num + node = ListNode(num) + # 如果队列为空，则令头、尾结点都指向该结点 + if self.__front == 0: + self.__front = node + self.__rear = node + # 如果队列不为空，则将该结点添加到尾结点后 + else: + self.__rear.next = node + self.__rear = node + self.__size += 1 + + """ 出队 """ + def get(self): + num = self.peek() + # 删除头结点 + self.__front = self.__front.next + self.__size -= 1 + return num + + """ 访问队首元素 """ + def peek(self): + if self.size() == 0: + return -1 + return self.__front.val + + def to_array(self): + queue = [] + temp = self.__front + while temp: + queue.append(temp.val) + temp = temp.next + return queue + + +if __name__ == "__main__": + """ 初始化队列 """ + queue = LinkedListQueue() + + """ 元素入队 """ + queue.put(1) + queue.put(3) + queue.put(2) + queue.put(5) + queue.put(4) + print("队列 queue = ", queue.to_array()) + + """ 访问队首元素 """ + peek = queue.peek() + print("队首元素 front = ", peek) + + """ 元素出队 """ + get = queue.get() + print("出队元素 get = ", get) + print("出队后 queue = ", queue.to_array()) + + """ 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) diff --git a/codes/python/chapter_stack_and_queue/queue.py b/codes/python/chapter_stack_and_queue/queue.py index 52855b2..3f39d2d 100644 --- a/codes/python/chapter_stack_and_queue/queue.py +++ b/codes/python/chapter_stack_and_queue/queue.py @@ -1,10 +1,42 @@ ''' File: queue.py -Created Time: 2022-11-25 -Author: Krahets (krahets@163.com) +Created Time: 2022-11-29 +Author: Peng Chen (pengchzn@gmail.com) ''' -import sys, os.path as osp +import os.path as osp +import sys + sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__)))) from include import * +import queue + +if __name__ == "__main__": + """ 初始化队列 """ + queue = queue.Queue() + + """ 元素入队 """ + queue.put(1) + queue.put(3) + queue.put(2) + queue.put(5) + queue.put(4) + print("队列 queue = ", queue.queue) + + """ 访问队首元素 """ + peek = queue.queue[0] + print("队首元素 peek = ", peek) + + """ 元素出队 """ + get = queue.get() + print("出队元素 get = ", get) + print("出队后 queue = ", queue.queue) + + """ 获取队列的长度 """ + size = queue.qsize() + print("队列长度 size = ", size) + + """ 判断队列是否为空 """ + is_empty = queue.empty() + print("队列是否为空 = ", is_empty)