具体数学-扰动法

from scipy.special import combn = int (input("n: "))k = int (input("k: "))sum1 = 0for j in range(0, k):for i in range(0, n+1):sum1 = sum1 + (i**j)*comb(k+1,j)result = ((n+1)**(k+1) - sum1)/comb(k+1,k) print(result)

python 中计算排列组合：

1. 调用scipy计算

>> from scipy.special import comb, perm
>> perm(3, 2)
6.0
>> comb(3, 2)
3.0

2. 调用 itertools 获取排列组合的全部情况数

>> from itertools import combinations, permutations
>> permutations([1, 2, 3], 2)
<itertools.permutations at 0x7febfd880fc0># 可迭代对象
>> list(permutations([1, 2, 3], 2))
[(1, 2), (1, 3), (2, 1), (2, 3), (3, 1), (3, 2)]>> list(combinations([1, 2, 3], 2))
[(1, 2), (1, 3), (2, 3)]