Me too, actually, I had to look up lambda syntax =]

Good catch! Will refactor to account for this edge case, thanks!

There are minor typos in 2 of the formula images in the description. In the formula for Uy, the part (xa - xb) should be (xb - xa). In the formula for distance between points A and B, the part (yb - yc)**2 should be (yb - ya)**2.

Otherwise, nice kata!

Perfect! Nice kata, btw, I enjoyed the sparse instructions and having to rely on tests and feedback to build the needed objects.

The expected return value for area of a circle is incorrect. The formula for area of a circle is r * r * pi, but the tests expect r * pi instead. For example, the area of a circle with radius 2 (rounded to 2 decimal places) should be 12.57, but the test expects 6.28.

Perfect!

Random Tests fail if array of max subsets is in a different order:

Random Tests
length of the arrays = 20
array = [-2, -3, -4, 1, 8, -6, -7, 5, -6, 1, 7, -8, 10, 5, -3, -8, 3, -8, 8, -2]
[[[1, 7, -8, 10, 5], [10, 5]], 15] should equal [[[10, 5], [1, 7, -8, 10, 5]], 15]

Can the description be updated to specify in which order the max subsets are expected?

Good point, the call to loadData is not tested.

Does this require registering an Instagram account in order to obtain a valid access_token or client_id? Without it, I receive the following error:

{ meta: 
{ error_type: 'OAuthAccessTokenException',
code: 400,
error_message: 'The access_token provided is invalid.' } }

{ meta: 
{ error_type: 'OAuthParameterException',
code: 400,
error_message: 'The client_id provided is invalid and does not match a valid application.' } }

That's exactly what the problem was. After changing my code, all tests passed. Sorry for the inconvenience!

That's a possibility, although the non-random tests pass without issue. I'll recheck my code.

Random tests for Ruby appear to expect an empty array:

It should work for random inputs too - Expected: [], instead got: ["e", "w", "o", 0, {"c"=>8}, 8, 3, 7, {"w"=>4}, {"w"=>4}, 0, {"o"=>3}, 7, 7]