createCanvas(400, 400);

  kSubsetPermutations([1,2,3,4,5], 3);

}

​

function kSubsetPermutations(set, k, partial) {

    if (!partial) partial = [];// set default value on first call

    for (var element in set) {

        if (k > 1) {

            var set_copy = set.slice();//slice() creates copy of array

            set_copy.splice(element, 1);//splice() removes element from array

            kSubsetPermutations(set_copy, k - 1, partial.concat([set[element]]));

        }                                       // a.concat(b) appends b to copy of a

        else console.log("[" + partial.concat([set[element]]) + "] ");

    }

}