求所有 k 阶子列
这儿的 k 阶子列 和线性代数里边矩阵的 k 阶子式 差不多，子列个数也和组合的公式相符，所以我就不啰嗦了。
import itertools
input_list = [1, 2, 4, 3, 5]
n = len(input_list)
k = 3
for i in range(1, n + 1):
i_subsequence = itertools.combinations(input_list, i)
if i == k:
k_subsequence = list(i_subsequence)
print(k_subsequence)
[(1, 2, 4), (1, 2, 3), (1, 2, 5), (1, 4, 3), (1, 4, 5), (1, 3, 5), (2, 4, 3), (2, 4, 5), (2, 3, 5), (4, 3, 5)]
求最具竞争力的 k 阶子列
所谓最具竞争力，就是在相同位置上，对应的数更小，则更具竞争力。比如 (1, 2, 3) 比 (1, 2, 4) 更具竞争力。
import itertools input_list = [1, 2, 4, 3, 5] n = len(input_list) k = 3 k_subsequence = list(itertools.combinations(input_list, k)) k_subsequence.sort() print(k_subsequence[0])
(1, 2, 3)
