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)