Computer Science 320SC

Computer Science 320SC – (2024)

Programming Assignment 1

Due: Friday, July 26 (11:59pm)

Requirements

This first assignment lets you get familar with submission of simple (but correct and efficient) algorithms

to the CompSci 320 automated marker. There are two algorithms/programs required but three different

submissions for marks (two data sets for one of them). It is worth 5% of your total course marks. (Note

future programming assignments will require much more work to obtain the same number of marks so

you are encouraged to make a serious attempt on this one.)

Problem Statement 1: Computing GCD

Read in a sequence of 32-bit signed integers (several per line separated by spaces) until a single line

containing zero (0). There will be at most 1000 integers per line. For each line except for the last one,

compute the greatest common divisor (gcd) of that set of integers. Then output on a line the statement

“The gcd of the integers is x.” where x is the desired gcd. Note, for this problem, all answers should

be non-negative.

The input should be taken from keyboard/stdin/System.in.

Sample Input:

2 4 8

15 0 -5

6 20 25 5 30

28 21952 49 294 3822

0

The precisely formated output should be sent to console/stdout/System.out.

Sample Output:

The gcd of the integers is 2.

The gcd of the integers is 5.

The gcd of the integers is 1.

The gcd of the integers is 7.

Practice I/O

For all programs, the input should be taken from stdin and output stdout. A practice problem (no

marks) for this input will be available on the automarker. Instead of outputting the gcd, simply output

the number of integers for each test case on a line by itself (nothing else). The number of output lines

should be the same as the number of test cases being processed.

1Problem Statement 2: Minimum Double Pair

The input format for this problem is the same as in Problem 1 but all integers (per line) are assumed to

be different. We read in a sequence of 32-bit signed integers (several per line separated by spaces) until

a single line containing zero (0). For each line except for the last one, compute the smallest sum s such

that there are two different pairs of integers (x1, x2) and (y1, y2), where x1 < x2, x1 = y1 < y2 = x2,

that both sum to s (e.g., x1 + x2 = y1 + y2 = s). If such a sum s is possible, output on a line “yes: s”.

Otherwise output on a line “None”.

Sample Input:

2 1 3 4

10 20 40 45 5 15 25

24 23 8 29 31 5

10 20 50 51 52 53 54 12 15 16

0

Sample Output:

yes: 5

yes: 25

None

yes: 62

Submission

You need to use just one source file per problem. The file extension indictes which programming

language you are using.

You submit to our automated marking system http://www.cs.auckland.ac.nz/automated-marker. Lim

ited feedback will be given by the submission system (see Help/FAQ) and you are allowed to resubmit

up to 8 times per problem before a 20% penalty applies.

There is two marks awarded for Problem 1 and three marks awarded for Problem 2 (with the harder

input cases being worth one mark).

2