refactor: Follow the PEP 585 Typing standard (#439)

* Follow the PEP 585 Typing standard

* Update list.py

codes/python/chapter_computational_complexity/space_complexity.py

@@ -17,7 +17,7 @@ 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
+    nums: list[int] = [0] * 10000
     node = ListNode(0)
     # 循环中的变量占用 O(1) 空间
     for _ in range(n):
@@ -29,9 +29,9 @@ 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: list[int] = [0] * n
     # 长度为 n 的哈希表占用 O(n) 空间
-    mapp: Dict = {}
+    mapp = dict[int, str]()
     for i in range(n):
         mapp[i] = str(i)
 
@@ -44,16 +44,16 @@ 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: list[list[int]] = [[0] * n for _ in range(n)]
 
 def quadratic_recur(n: int) -> int:
     """ 平方阶（递归实现） """
     if n <= 0: return 0
     # 数组 nums 长度为 n, n-1, ..., 2, 1
-    nums: List[int] = [0] * n
+    nums: list[int] = [0] * n
     return quadratic_recur(n - 1)
 
-def build_tree(n: int) -> Optional[TreeNode]:
+def build_tree(n: int) -> TreeNode | None:
     """ 指数阶（建立满二叉树） """
     if n == 0: return None
     root = TreeNode(0)
@@ -74,5 +74,5 @@ if __name__ == "__main__":
     quadratic(n)
     quadratic_recur(n)
     # 指数阶
-    root: Optional[TreeNode] = build_tree(n)
+    root = build_tree(n)
     print_tree(root)