Given two integers
k, return all possible combinations of
k numbers out of
1 2 3 ... n.
Make sure the combinations are sorted.
1. Within every entry, elements should be sorted.
[1, 4] is a valid entry while
[4, 1] is not.
2. Entries should be sorted within themselves.
n = 4 and
k = 2, a solution is:
[ [1,2], [1,3], [1,4], [2,3], [2,4], [3,4], ]
Warning : DO NOT USE LIBRARY FUNCTION FOR GENERATING COMBINATIONS.
Example : itertools.combinations in python.
If you do, we will disqualify your submission retroactively and give you penalty points.