#63
Group a Sequence
| Difficulty: | Easy |
| Topics: | core-functions |
Given a function f and a sequence s,
write a function which returns a map.
The keys should be the values of f applied to each item in s.
The value at each key should be a vector
of corresponding items in the order they appear in s.
 | (= (__ #(> % 5) #{1 3 6 8}) {false [1 3], true [6 8]}) |
| (= (__ #(apply / %) [[1 2] [2 4] [4 6] [3 6]])
{1/2 [[1 2] [2 4] [3 6]], 2/3 [[4 6]]}) |
| (= (__ count [[1] [1 2] [3] [1 2 3] [2 3]])
{1 [[1] [3]], 2 [[1 2] [2 3]], 3 [[1 2 3]]}) |
Special Restrictions
group-by