Add typing annotations to Python codes. (#411)

codes/python/chapter_stack_and_queue/array_queue.py

@@ -4,59 +4,57 @@ Created Time: 2022-12-01
 Author: Peng Chen (pengchzn@gmail.com)
 """
 
-import os.path as osp
-import sys
-
+import sys, os.path as osp
 sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
 from modules import *
 
 class ArrayQueue:
     """ 基于环形数组实现的队列 """
-    def __init__(self, size):
+    def __init__(self, size: int) -> None:
         """ 构造方法 """
-        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
+        self.__nums: List[int] = [0] * size  # 用于存储队列元素的数组
+        self.__front: int = 0          # 队首指针，指向队首元素
+        self.__size: int = 0           # 队列长度
 
-    def capacity(self):
+    def capacity(self) -> int:
         """ 获取队列的容量 """
         return len(self.__nums)
 
-    def size(self):
+    def size(self) -> int:
         """ 获取队列的长度 """
         return self.__size
 
-    def is_empty(self):
+    def is_empty(self) -> bool:
         """ 判断队列是否为空 """
         return self.__size == 0
 
-    def push(self, num):
+    def push(self, num: int) -> None:
         """ 入队 """
         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()
+        rear: int = (self.__front + self.__size) % self.capacity()
         # 将 num 添加至队尾
         self.__nums[rear] = num
         self.__size += 1
 
-    def poll(self):
+    def poll(self) -> int:
         """ 出队 """
-        num = self.peek()
+        num: int = 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
 
-    def peek(self):
+    def peek(self) -> int:
         """ 访问队首元素 """
         assert not self.is_empty(), "队列为空"
         return self.__nums[self.__front]
 
-    def to_list(self):
+    def to_list(self) -> List[int]:
         """ 返回列表用于打印 """
-        res = [0] * self.size()
-        j = self.__front
+        res: List[int] = [0] * self.size()
+        j: int = self.__front
         for i in range(self.size()):
             res[i] = self.__nums[(j % self.capacity())]
             j += 1
@@ -77,24 +75,24 @@ if __name__ == "__main__":
     print("队列 queue =", queue.to_list())
 
     """ 访问队首元素 """
-    peek = queue.peek()
+    peek: int = queue.peek()
     print("队首元素 peek =", peek)
 
     """ 元素出队 """
-    poll = queue.poll()
+    poll: int = 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()
+    size: int = queue.size()
     print("队列长度 size =", size)
 
     """ 判断队列是否为空 """
-    is_empty = queue.is_empty()
+    is_empty: bool = 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());
+        queue.push(i)
+        queue.poll()
+        print("第", i, "轮入队 + 出队后 queue = ", queue.to_list())