CODEWITHSUNDEEP
pythonlist
ARIJIT SINGH
ARIJIT SINGH

Reputation: 90

Find sublists of an array

Given Arr=[10,34,20,19], N=4, K=2, and to obtain the list Reqd=[[[10],[34,20,19]],[[10,34],[20,19]],[[10,34,20],[19]]]

I tried using the itertools.permutation(Arr,2), but did not find the desired result. How do I find the Reqd list?

Upvotes: 0

Views: 52

Answers (1)

Andrej Kesely
Andrej Kesely

Reputation: 195438

Try:

Arr = [10, 34, 20, 19]
N = 4
K = 2


valid_combinations = []


def all_combinations(current):
    s = sum(current)
    if len(current) > K or s > N:
        return

    if s == N and len(current) == K:
        valid_combinations.append(current)
        return

    for val in range(1, N + 1):
        all_combinations(current + [val])


all_combinations([])

out = []
for comb in valid_combinations:
    idx = 0
    out.append([])
    for c in comb:
        out[-1].append(Arr[idx : idx + c])
        idx += c
print(out)

Prints:

[[[10], [34, 20, 19]], [[10, 34], [20, 19]], [[10, 34, 20], [19]]]

For:

Arr = [10, 34, 20, 19]
N = 4
K = 3

Prints:

[[[10], [34], [20, 19]], [[10], [34, 20], [19]], [[10, 34], [20], [19]]]

Upvotes: 1

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