Permutations of a certain length of a list (combinations, choose k of n, unordered) (v2)

ListPermutation.java

import com.google.common.collect.Lists;
import java.util.List;

public class ListPermutation {

    public static void main(String[] args) {

        for (int i = 0; i <= 6; i++) {
            System.out.println("Take " + i + " of 5: " + permutations(Lists.newArrayList(1, 2, 3, 4, 5), i));
        }
        System.out.println("Take 1 of 1: " + permutations(Lists.newArrayList(1), 1));
        System.out.println("Take 1 of 0: " + permutations(Lists.newArrayList(), 1));

    }

    public static <T> List<List<T>> permutations(List<T> input, int select) {
        List<List<T>> res = Lists.newArrayList();
        if (select == 0) {
            res.add(Lists.<T>newArrayList());
            return res;
        }

        for (int i = 1; i < input.size(); i++) {
            T current = input.get(i);
            List<T> subListBeforeCurrent = input.subList(0, i);

            for (List<T> permutation : permutations(subListBeforeCurrent, select - 1)) {
                permutation.add(current);
                res.add(permutation);
            }
        }

        return res;
    }
}