O-LevelComputer ScienceAlgorithm design and problem-solving2210/21 · May/June 2017 · Q65 Marks

This flowchart inputs a range of temperatures in degrees Fahrenheit. As each temperature is input, it is compared with the previous highest temperature. If it is higher than the current highest, it replaces the previous highest temperature and then it is converted to degrees Celsius. For ease of calculation, the final step of the Fahrenheit to Celsius conversion has been approximated as division by 2. When -1 is entered, the input process stops and the highest temperature (in both Fahrenheit and Celsius) is output. [Figure 6.1]

(a)Complete the trace table for the input data: 68, 46, 50, 86, 65, 50, 40, 30, -1 Trace Table Columns: HighF, HighC, TempF, OUTPUT[5]

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Mark scheme

Marking points from the official mark scheme (May/June 2017). The mark or mark type is shown in brackets.

[5] 1 Mark for each correct cell entry
HighF: -100, 68, 68, 68, 86, 86, 86, 86, 86, 86
HighC: -100, 18, 18, 18, 27, 27, 27, 27, 27, 27
TempF: 68, 46, 50, 86, 65, 50, 40, 30, -1
The literal correct output is "The highest temperature is, 86 Fahrenheit, 27 Celsius."
1 mark for values 86 and 27, 1 mark for correct output words, spacing and punctuation.

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