Add python code for queue

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)