Sorry for accusing you of that. :P Problem may have been that the reference solution was modifying its input.

Is this issue resolved now that JohanWiltink has updated the javascript translation?

You were modifying the input, weren't you? :]

There was a little problem with my code which made it super slow. Now only O(n) solutions should pass.

Glad you liked it :)

Hmm. I wrote the Python and Ruby translations but not the JavaScript because I was unfamiliar with the bigInt library. Thanks for letting me know, I'll have to see about trying to make it so true n^2 solutions (and your second solution does appear to be one) fail. That's certainly the shortest solution I've seen yet :)

If you were mutating the array, then the tests were generated improperly, Now the tests are corrected to be generated correctly

sorry, the reference solution still returns false on that test case.

Details in performance tests:

100 Random Tests --- Testing for code performance
 Your code should run as fast as a rocket ;-)
 Log
Testing for:
arr = [...1000001 elements] 
Test Passed: Value == '12ms'
Test Passed: Value == 557872
 Log
Testing for:
arr = [...1000001 elements] 
Test Passed: Value == '6ms'
Test Passed: Value == 596695
 Log
Testing for:
arr = [...1000001 elements] 
Test Passed: Value == '5ms'
Test Passed: Value == 594965
 Log
Testing for:
arr = [...1000001 elements] 
Test Passed: Value == '7ms'
Test Passed: Value == 549057

So, it seems no problem ;-)

My solution's results:

Test Results:
 Basic Tests
 It should works for basic tests (5 of 5 Assertions)
Completed in 7ms
 100 Random Tests --- Testing for correctness of solution
 It should works for random tests too. (100 of 100 Assertions)
Completed in 33ms
 100 Random Tests --- Testing for code performance
 Your code should run as fast as a rocket ;-) (200 of 200 Assertions)
Completed in 5700ms
 Log
Your code running in range 5ms - 12ms

Random test is reusing the same array object to perform its own computation to check if your solution is valid, so you shouldn't mutate the original array.

Thanks, glad you liked it!

Thanks, @kazk!

@Grae-Drake, the example is correct.

The idea is:

numbers: [a, b, c, d], rules: [f, g]
[f(a, b), c, d]
[g(f(a, b), c), d]
f(g(f(a, b), c), d)

Applied to numbers [2.0, 2.0, 3.0, 4.0] and rules [(a,b) => a + b, (a,b) => a - b]

[(2.0 + 2.0), 3.0, 4.0]
[((2.0 + 2.0) - 3.0), 4.0]
(((2.0 + 2.0) - 3.0) + 4.0)

(steps from the description)
1. Rule 1: First number + second number -> 2.0 + 2.0 = 4.0
           2.0 + 2.0
2. Rule 2: result from step before - third number -> 4.0 - 3.0 = 1.0
           (2.0 + 2.0) - 3.0
3. Rule 1: result from step before + forth number -> 1.0 + 4.0 = 5.0
           ((2.0 + 2.0) - 3.0) + 4.0

CodeWars seems to have made some changes. I revised the kata and it should work for you now.