Keep the winning record and handle every tie

Knowing the highest mark is not enough when you need to name the students who earned it. Keep the relevant record ID together with the maximum value, and decide what to do when a later score ties it.

One owner: first or last depends on the comparison #

With a first-record seed, updating one owner only when a score is strictly greater preserves the first maximum encountered. Updating on greater-than-or-equal preserves the last maximum encountered. Both return one valid maximum owner, but neither reports all ties.

All owners: three branches #

If input is empty: report "No maximum"
Read first record X
Max = X.Mathematics
Owners = [X.CardNo]
For each remaining record X {
    if (X.Mathematics > Max) {
        Max = X.Mathematics
        Owners = [X.CardNo]
    }
    else if (X.Mathematics == Max) {
        Append X.CardNo to Owners
    }
}

On a new higher score, clear old owners by replacing the list. On a tie, append without clearing. On a lower score, change neither. An if/else-if structure prevents the same newly accepted card from also entering a second equality branch and being added twice.

Trace the supplied maths winners #

At the end, the maximum is 97 and both IDs remain. IDs are more reliable for retrieving full records than names alone, because different people can have the same name.

Tutorial: customer behind the largest single bill #

Tutorial 2.6 carries both MaxBillAmount and MaxBillCustomer, and reports Akshaya with Rs 4174. This answers who paid the largest individual bill in that dataset, not who spent the most across all their bills. If a later bill ties the amount and all ties are requested, retain both relevant bill IDs or customers under a stated policy.

Source: Lecture 2.7; Tutorial 2.6. Small teaching datasets and diagrams are prepared for these notes; lecture and tutorial totals are identified explicitly.