SECTION 11 / 15

Ties and impossible criteria: finish the specification

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A calculation can be mechanically correct while the problem rules remain incomplete. Three physical prize slots cannot always fit everyone tied at the boundary. Representation rules can also be impossible if no eligible student belongs to a required category.

A hypothetical four-way tie illustrates why exactly three prizes need a stated tie policy; these275-point cards are a teaching example, not additional course records.
A hypothetical four-way tie illustrates why exactly three prizes need a stated tie policy; these275-point cards are a teaching example, not additional course records.

Separate score levels from prize slots

SituationCan three prize slots include everyone shown?
Three students tied for firstYes: all three can receive a prize.
Four students tied for firstNo: choose a stated tie-break or allow more prizes.
One first; two students tied for secondYes: three people in total.
One first; three students tied for secondNo: four people are competing for three slots.

A deterministic display order such as CardNo does not automatically make an award policy fair. Say whether ties lead to shared prizes, another documented criterion, or a request for a revised rule. Do not silently let the input order decide.

Check representation after eligibility

Our three actual winners include M and F, so no adjustment is needed. In a different dataset, one approach is to replace the lowest selected person with the highest eligible person from the missing category. If no such eligible person exists, the current rules are infeasible. Repeating a search without a failure condition will not create a valid candidate.

The lecture discusses excluding a lowest selected person and repeating. Each attempt must make progress and terminate when eligible possibilities are exhausted. Never remove a required condition silently to force an answer.

Try it yourself

Can four first-place ties all fit three prizes?

Show explained answer

No. The rules need a tie policy or permission to award more than three prizes.

Try it yourself

What if no eligible F record exists under a rule requiring M and F?

Show explained answer

Report that the requirements cannot all be met. Further identical scans will not help.

Try it yourself

Is using input order as an unstated tie-break acceptable?

Show explained answer

No. It produces an arbitrary outcome that changes if the cards are shuffled.

Try it yourself

Do the actual winners satisfy the lecture’s representation rule?

Show explained answer

Yes. Rahul is M; Deepika and Abirami are F.

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