Collect everyone at the top three distinct mark levels

The earlier TopThreeMarks procedure finds distinct score levels. Maths has levels 97, 93 and 89; Physics 92, 91 and 88; Chemistry 97, 93 and 92. Include every student whose mark is at least the third level. Ties mean a subject’s list can contain more than three people.

MathsIDs = []; PhysicsIDs = []; ChemistryIDs = []
foreach X in ScoreRecords:
    if X.Mathematics >= 89:
        MathsIDs = MathsIDs ++ [X.CardNo]
    if X.Physics >= 88:
        PhysicsIDs = PhysicsIDs ++ [X.CardNo]
    if X.Chemistry >= 92:
        ChemistryIDs = ChemistryIDs ++ [X.CardNo]

Learn the cutoffs first, then construct membership lists with fixed cutoffs. Three independent IF statements let Rahul enter all three lists. Using strict > would wrongly discard students exactly at the boundary. Computing the cutoffs by separate consuming table scans also requires restoring the table between calls.

The lecture’s zero-initialized top-three procedure relies on non-negative marks and this dataset having enough positive distinct scores. A general implementation should use empty slots or an explicit unavailable result when fewer than three distinct values exist. Equality must not shift a repeated top mark into a new distinct level.