How to find which items in list of lists is equal to another list

问题

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]

回答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])

来源：https://stackoverflow.com/questions/62765897/how-to-find-which-items-in-list-of-lists-is-equal-to-another-list