Simplify the declarations of the Python code.

codes/python/chapter_computational_complexity/space_complexity.py

@@ -19,12 +19,12 @@ def function() -> int:
 def constant(n: int) -> None:
     """常数阶"""
     # 常量、变量、对象占用 O(1) 空间
-    a: int = 0
-    nums: list[int] = [0] * 10000
+    a = 0
+    nums = [0] * 10000
     node = ListNode(0)
     # 循环中的变量占用 O(1) 空间
     for _ in range(n):
-        c: int = 0
+        c = 0
     # 循环中的函数占用 O(1) 空间
     for _ in range(n):
         function()
@@ -33,7 +33,7 @@ def constant(n: int) -> None:
 def linear(n: int) -> None:
     """线性阶"""
     # 长度为 n 的列表占用 O(n) 空间
-    nums: list[int] = [0] * n
+    nums = [0] * n
     # 长度为 n 的哈希表占用 O(n) 空间
     mapp = dict[int, str]()
     for i in range(n):
@@ -51,7 +51,7 @@ def linear_recur(n: int) -> None:
 def quadratic(n: int) -> None:
     """平方阶"""
     # 二维列表占用 O(n^2) 空间
-    num_matrix: list[list[int]] = [[0] * n for _ in range(n)]
+    num_matrix = [[0] * n for _ in range(n)]
 
 
 def quadratic_recur(n: int) -> int:
@@ -59,7 +59,7 @@ def quadratic_recur(n: int) -> int:
     if n <= 0:
         return 0
     # 数组 nums 长度为 n, n-1, ..., 2, 1
-    nums: list[int] = [0] * n
+    nums = [0] * n
     return quadratic_recur(n - 1)
 
 

codes/python/chapter_computational_complexity/time_complexity.py

@@ -7,8 +7,8 @@ Author: Krahets (krahets@163.com)
 
 def constant(n: int) -> int:
     """常数阶"""
-    count: int = 0
-    size: int = 100000
+    count = 0
+    size = 100000
     for _ in range(size):
         count += 1
     return count
@@ -16,7 +16,7 @@ def constant(n: int) -> int:
 
 def linear(n: int) -> int:
     """线性阶"""
-    count: int = 0
+    count = 0
     for _ in range(n):
         count += 1
     return count
@@ -24,7 +24,7 @@ def linear(n: int) -> int:
 
 def array_traversal(nums: list[int]) -> int:
     """线性阶（遍历数组）"""
-    count: int = 0
+    count = 0
     # 循环次数与数组长度成正比
     for num in nums:
         count += 1
@@ -33,7 +33,7 @@ def array_traversal(nums: list[int]) -> int:
 
 def quadratic(n: int) -> int:
     """平方阶"""
-    count: int = 0
+    count = 0
     # 循环次数与数组长度成平方关系
     for i in range(n):
         for j in range(n):
@@ -43,7 +43,7 @@ def quadratic(n: int) -> int:
 
 def bubble_sort(nums: list[int]) -> int:
     """平方阶（冒泡排序）"""
-    count: int = 0  # 计数器
+    count = 0  # 计数器
     # 外循环：待排序元素数量为 n-1, n-2, ..., 1
     for i in range(len(nums) - 1, 0, -1):
         # 内循环：冒泡操作
@@ -59,8 +59,8 @@ def bubble_sort(nums: list[int]) -> int:
 
 def exponential(n: int) -> int:
     """指数阶（循环实现）"""
-    count: int = 0
-    base: int = 1
+    count = 0
+    base = 1
     # cell 每轮一分为二，形成数列 1, 2, 4, 8, ..., 2^(n-1)
     for _ in range(n):
         for _ in range(base):
@@ -79,7 +79,7 @@ def exp_recur(n: int) -> int:
 
 def logarithmic(n: float) -> int:
     """对数阶（循环实现）"""
-    count: int = 0
+    count = 0
     while n > 1:
         n = n / 2
         count += 1
@@ -107,7 +107,7 @@ def factorial_recur(n: int) -> int:
     """阶乘阶（递归实现）"""
     if n == 0:
         return 1
-    count: int = 0
+    count = 0
     # 从 1 个分裂出 n 个
     for _ in range(n):
         count += factorial_recur(n - 1)
@@ -130,7 +130,7 @@ if __name__ == "__main__":
 
     count: int = quadratic(n)
     print("平方阶的计算操作数量 =", count)
-    nums: list[int] = [i for i in range(n, 0, -1)]  # [n,n-1,...,2,1]
+    nums = [i for i in range(n, 0, -1)]  # [n, n-1, ..., 2, 1]
     count: int = bubble_sort(nums)
     print("平方阶（冒泡排序）的计算操作数量 =", count)
 

codes/python/chapter_computational_complexity/worst_best_time_complexity.py

@@ -10,7 +10,7 @@ import random
 def random_numbers(n: int) -> list[int]:
     """生成一个数组，元素为: 1, 2, ..., n ，顺序被打乱"""
     # 生成数组 nums =: 1, 2, 3, ..., n
-    nums: list[int] = [i for i in range(1, n + 1)]
+    nums = [i for i in range(1, n + 1)]
     # 随机打乱数组元素
     random.shuffle(nums)
     return nums
@@ -29,7 +29,7 @@ def find_one(nums: list[int]) -> int:
 """Driver Code"""
 if __name__ == "__main__":
     for i in range(10):
-        n: int = 100
+        n = 100
         nums: list[int] = random_numbers(n)
         index: int = find_one(nums)
         print("\n数组 [ 1, 2, ..., n ] 被打乱后 =", nums)