Wordle Feedback

The uppercase strings answer and guess have equal length and contain no repeated letter within either word.
Return one feedback character per guess position: G when the letter and position match, Y when the letter occurs elsewhere in answer, and _ when the letter is absent.

Function
wordleFeedback(answer: String, guess: String) → String

Examples
Example 1
answer = "ABCD"
guess = "ACDE"
return = "GYY_"
A is exact, C and D are present at other positions, and E is absent.
Example 2
answer = "PHONE"
guess = "HOWLS"
return = "YY___"
H and O occur in the answer but both are misplaced.
Example 3
answer = "PHONE"
guess = "WALKS"
return = "_____"
No guessed letter occurs in the answer.

Constraints
1 <= answer.length == guess.length <= 26.
Both strings contain distinct uppercase English letters.

The trick is that distinct letters kill the hard part. No double-counting, no greens-first bookkeeping. Build a set (or a 26-slot lookup) from answer. Then walk guess by index. If guess[i] equals answer[i], write G. Else if guess[i] is in the set, write Y. Otherwise write _. That's O(n) time and O(1) space since the alphabet caps at 26. The common pitfall is overengineering: people port the full Wordle algorithm with frequency counts and two passes, then introduce bugs. Another slip is using answer.indexOf inside the loop, which works but is needlessly quadratic. Check Example 2 by hand: HOWLS against PHONE gives H and O present but misplaced, so YY___. If you freeze during the live OA, StealthCoder is the safety net that reads the problem on screen and gives you this loop, so you can submit and move on.

If this hits your live OA and you blank, StealthCoder solves it in seconds, invisible to the proctor.