IGCSE Computer Science Paper 2 Definitions Worksheet: 7d Standard Methods of Solution (Modules 296–306)
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Key terms
Write what each term means, in your own words.
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IF Found = TRUE THEN OUTPUT "Found at ", Index ELSE OUTPUT "Not found" ENDIF
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trace table
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bubble sort
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Temp ← Marks[Index]
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IF Marks[Index] > Marks[Index + 1] THEN
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FOR Pass ← 1 TO n - 1
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UNTIL Swapped = FALSE
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bubble sort trace
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logic error
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key words
Answer Key
IGCSE Computer Science Paper 2 · Modules 296–306 · Student wording will vary for definitions
1IF Found = TRUE THEN OUTPUT "Found at ", Index ELSE OUTPUT "Not found" ENDIF — After the search loop, check the Found flag: if TRUE, output the position (Index) where the target was found, otherwise output a not-found message. Covers first, last and missing items.
2trace table — A table that records the index, the element compared and the Found flag on each pass of a linear search, so you can follow it step by step.
3bubble sort — A sorting method that compares neighbouring items and swaps them if in the wrong order, repeating passes until the list is sorted. The largest value bubbles to the end each pass.
4Temp ← Marks[Index] — Saves the value of Marks[Index] in Temp so it is not lost. Marks[Index] can then be overwritten, and Temp is copied into Marks[Index + 1] to finish the swap.
5IF Marks[Index] > Marks[Index + 1] THEN — One pass: a FOR loop compares each item with its neighbour and swaps them if the first is larger, so the biggest value moves to the end.
6FOR Pass ← 1 TO n - 1 — Outer loop of a bubble sort: it runs n - 1 passes. Inside it, an inner FOR loop compares neighbours and swaps them if out of order, so the whole array ends up sorted.
7UNTIL Swapped = FALSE — A BOOLEAN flag set to FALSE before each pass and to TRUE whenever a swap happens. The bubble sort stops when a full pass leaves it FALSE, meaning no swaps were needed and the data is sorted.
8bubble sort trace — Writing out the array after every pass, showing each comparison and swap, plus the Temp and Swapped values, to see how a bubble sort puts the data in order.
9logic error — A mistake in an algorithm's steps that lets it run but gives wrong results, e.g. a total not set to 0, a loop going past the array end, or using > instead of <.
10key words — Words in a problem, like add up, how many, highest, average, find or put in order, that show which standard method to use: totalling, counting, max/min, average, search or sort.