How to get a combination of lists from a large list?

Question

I have a list with ten elements, for example:

{x1,x2,x3,x4,x5,x6,x7,x8,x9,x10}

I want to have all the combinations of the 3 elements-list like below:

{{x1,x2,x3},{x1,x2,x4},{x1,x2,x5},.....,{x2,x3,x4},{x2,x3,x5},......}

I cannot find a function to do this.

Wait, do you want to allow for permutations, I mean, do you want to have also the combinations {x1,x2,x3} and {x2,x1,x3}? If so, then this might help Select[Permutations[Array[x, 10], 3], Length[#] == 3 &] — Mauricio Fernández, Nov 24 '16 at 09:32
@Mauricio Lobos.No, I don't want permutations. just{x1,x2,x3}and other combinations. — ZHANG Juenjie, Nov 24 '16 at 10:28

score 3 · Accepted Answer · answered Nov 24 '16 at 09:43

lst = {x1, x2, x3, x4, x5};

Subsets[lst, {3}]

{{x1, x2, x3}, {x1, x2, x4}, {x1, x2, x5}, {x1, x3, x4}, {x1, x3, x5}, {x1, x4, x5}, {x2, x3, x4}, {x2, x3, x5}, {x2, x4, x5}, {x3, x4, x5}}

Or, if the order matters,

Permutations[lst, {3}]

1 Answers1