yes, absolutely true! Although I explained this point in a comment before. But then I didn’t know how to use formatting, and it was very difficult to understand the code that I wrote in the comment.
It's a pursuit of brevity.

Yes, thanks, really very stupid mistake.))))
The number finds itself, as in a mirror

You also have O(n), if you want to find solutions with the best result, then there are other sites for this, where this is emphasized. Or you can post 2 solutions. One is short, the other is optimal.
For all arrays of type [0,0,0,1] you have the same result.

I don't think you'll get extra points for fast execution here.

Agree with you! But I did not redo it, just one of the solutions. Monument to curvature. Now I would write it differently

by js guru - OverZealous

I would put "Clever" but too short solution in comparison with other similar ones, just 2 pages))

Ok, I guess I can't understand the task. As I understand it, the results should be as follows:
[SOUTH, EAST, SOUTH, SOUTH, EAST, NORTH, EAST, NORTH]=>[EAST,SOUTH,EAST,EAST].
[NORTH, EAST, SOUTH, NORTH, SOUTH, SOUTH, SOUTH, NORTH, EAST, NORTH, NORTH, EAST, SOUTH, EAST, SOUTH]=>[EAST,EAST,EAST,EAST,SOUTH]
[EAST, NORTH, EAST, SOUTH, NORTH, NORTH, SOUTH, EAST, SOUTH, SOUTH]=>[EAST,EAST,EAST,SOUTH]
I missed "Write a function dirReduc which will take an array of strings and returns an array of strings with the needless directions removed (W<->E or S<->N side by side)."
Sorry, "side by side" by google translator like: "Near", "in the same array".
If there was such an example, I would understand the error right away

C# tests are wrong:
test(7):
input=[SOUTH, EAST, SOUTH, SOUTH, EAST, NORTH, EAST, NORTH]
Test Failed
Expected is <System.String[8]>, actual is <System.String[4]>.
But 4 is right!
test(10):
input=[NORTH, EAST, SOUTH, NORTH, SOUTH, SOUTH, SOUTH, NORTH, EAST, NORTH, NORTH, EAST, SOUTH, EAST, SOUTH]
Test Failed
Expected is <System.String[11]>, actual is <System.String[5]>.
test(8):
input=[EAST, NORTH, EAST, SOUTH, NORTH, NORTH, SOUTH, EAST, SOUTH, SOUTH]
Expected is <System.String[6]>, actual is <System.String[4]>

For C #, the conditions are different. Needed for (t * 2> 9) -> (t minus 9), not return 9. Therefore, tests fail

by formula <ms, brut force 1ms