如何查找列表列表中的哪些项目等于另一个列表

Question

I have a list of lists that looks like this:

[[0],
[0, 1, 2],
[2],
[3],
[4],
[5],
[0, 1, 2, 3, 4, 5, 6, 7],
[7],
[8],
[9],
[8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18],
[11],
[11, 12, 13, 14, 15, 16, 17, 18],
[13],
[14],
[14, 15, 16, 17, 18],
[16, 17, 18],
[17],
[17, 18]]

I am trying to find the least number of items in the list, when concatenated, that equal the full range of the list. In this case, the full range of the list is this:

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]

So in this case, these two items from the list of lists would equal the full range:

[0]
[0, 1, 2]
[2]
[3]
[4]
[5]
---> [0, 1, 2, 3, 4, 5, 6, 7]
[7]
[8]
[9]
---> [8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18]
[11]
[11, 12, 13, 14, 15, 16, 17, 18]
[13]
[14]
[14, 15, 16, 17, 18]
[16, 17, 18]
[17]
[17, 18]

Answer 1

One way using itertools.permutations and chain :

from itertools import permutations, chain

starget = sorted(target)
for i in range(2, len(target)):
    for perm in permutations(l, i):
        if sorted(chain(*perm)) == starget:
            print(i, perm)
            break
    break

Output:

2 ([0, 1, 2, 3, 4, 5, 6, 7], [8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18])