[sjs1234]

Ambiguity is something a programmer needs to deal with at work. Riddles are not. Open ended questions are exactly what you want to use to evaluate someone. Riddles fail because there is an expected answer, not because the form of the question is ambiguous.

Some coding questions as asked in interviews are actually riddles in practice because the interviewer is unskilled. Those 'coding questions' are worse than the obviously bad riddles because it is harder to tell that the feedback is slanted.