mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-29 10:06:28 +08:00
78 lines
1.7 KiB
Python
78 lines
1.7 KiB
Python
"""
|
|
File: space_complexity.py
|
|
Created Time: 2022-11-25
|
|
Author: Krahets (krahets@163.com)
|
|
"""
|
|
|
|
import sys, os.path as osp
|
|
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
|
|
from include import *
|
|
|
|
""" 函数 """
|
|
def function():
|
|
# do something
|
|
return 0
|
|
|
|
""" 常数阶 """
|
|
def constant(n):
|
|
# 常量、变量、对象占用 O(1) 空间
|
|
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 = 0
|
|
# 循环中的函数占用 O(1) 空间
|
|
for _ in range(n):
|
|
function()
|
|
|
|
""" 线性阶 """
|
|
def linear(n):
|
|
# 长度为 n 的列表占用 O(n) 空间
|
|
nums = [0] * n
|
|
# 长度为 n 的哈希表占用 O(n) 空间
|
|
mapp = {}
|
|
for i in range(n):
|
|
mapp[i] = str(i)
|
|
|
|
""" 线性阶（递归实现） """
|
|
def linearRecur(n):
|
|
print("递归 n =", n)
|
|
if n == 1: return
|
|
linearRecur(n - 1)
|
|
|
|
""" 平方阶 """
|
|
def quadratic(n):
|
|
# 二维列表占用 O(n^2) 空间
|
|
num_matrix = [[0] * n for _ in range(n)]
|
|
|
|
""" 平方阶（递归实现） """
|
|
def quadratic_recur(n):
|
|
if n <= 0: return 0
|
|
nums = [0] * n
|
|
print("递归 n =", n, "中的 nums 长度 =", len(nums))
|
|
return quadratic_recur(n - 1)
|
|
|
|
""" 指数阶（建立满二叉树） """
|
|
def build_tree(n):
|
|
if n == 0: return None
|
|
root = TreeNode(0)
|
|
root.left = build_tree(n - 1)
|
|
root.right = build_tree(n - 1)
|
|
return root
|
|
|
|
|
|
""" Driver Code """
|
|
if __name__ == "__main__":
|
|
n = 5
|
|
# 常数阶
|
|
constant(n)
|
|
# 线性阶
|
|
linear(n)
|
|
linearRecur(n)
|
|
# 平方阶
|
|
quadratic(n)
|
|
quadratic_recur(n)
|
|
# 指数阶
|
|
root = build_tree(n)
|
|
print_tree(root)
|