Reference solution is incorrect:

courier(['e1', 'e2', 'n3', 'n3', 's2', 's2'], 3)
30 should equal 32

Delivering every package without counting package loading time takes 26 minutes. It then should take only 2 loads to deliver all packages (6 / 2 = 3), not 3, so the expected time should be 26 + 2 * 2 = 30, not 32.

(Loading time is independent of direction, otherwise the fixed tests will not match)

C#: method name should be PascalCase (Please refer to implementation of backward compatibility here )

Java translation

Should work as intendet, if it is OK it can be approved.

Unicode symbols are not guaranteed to render in the browser, and IMO there's no point in using them instead of simple headers and ordered/unordered lists.

Could you please explain
why T9("eeee",["dear"]) should return ["dear"],
but T9("eeeee",["dear"]) should return []?

The random tests are not reliable. This solution is incorrect but it can pass the random tests.

Your task is to return an array of the possible words that the user misswritten

Define "miswritten".

Duplicate =/

• You need more than 20 random tests.

• You also need to test longer strings. A length of 2 isn't enough.

Every string starts with an empty string, don't you think? You should specify this case in the description.

Also, may be a duplicate (but I haven't bothered to search)