The American University in Cairo
Computer Science Department
CSCI 106
Instructor: …………….
Final EXAM
Last Name : ...........................................................
First Name: ...........................................................
Fall 2003
ID: .................................
Section No: 03
EXAMINATION INSTRUCTIONS
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Do not turn this page until asked to do so.
Exam time is 120 minutes.
Put the answers on the same question sheet, do not use any additional papers, even for scratch.
Write your name, ID, section no. in the indicated places.
Read the exam instructions.
Read the honesty policy.
Sign the following statement.
HONESTY POLICY
Cheating in Exams is a violation of the honesty policy of AUC. Whispering, talking, looking at
someone else’s paper, or copying from any source is considered cheating. Any one who does any
of these actions or her/his answers indicates that she/he did any of them, will receive a punishment
ranging from zero in this exam to failing the course. If repeated, it may lead to dismissal from
AUC.
I have read the honesty policy and exam instructions and I am presenting this exam as
entirely my effort.
Signature: _______________
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DO NOT USE THIS SECTION
Question
Points
1
15
2
20
3
30
4
15
5
20
Total
100
1
Grade
Question 1
A company wants to transmit data oer the Internet, but is concerned that its communication lines be
tapped. All of the data are transmitted as four-digit integers. The company has asked you to write a
program that encrypts the data so that it can be transmitted more securely. Yoyr program should read
a four-digit integer and encrypt it as follows: Replace each each digit by (the sum of that digit plus 7)
modulus 10. Then swap the first digit with the third, swap the second digit with the fourth and print
the encrypted integer.
Bonus Problem: Write a separate program that inputs an incrypted four-digit integer and
decrypts it to form the original number.
Question 2
Use an array to read in 20 numbers, each of which is between 10 and 100, inclusive. As each number
is read, print it only if it is not a duplicate of a number already read. Provide for the “worst case” in
which all 20 numbers are different.
Question 3
Write a function that takes an integer value and returns the number with its digits reversed. For
example, given the number 7631, the function should return 1367.
Question 4
Write a function qualityPoints that inputs a student’s average and returns the letter grade ‘A’ if a
student’s average is 90-100, ‘B’ if the average is 80-89, ‘C’ if the average is 70-79, ‘D’ if the average
is 60-69, and ‘F’ if the average is lower than 60.
Question 5
A company pays its employees as managers (who receive a fixed weekly salary), hourly workers
(who receive a fixed hourly wage for up to the first 40 hours they work and “time-and-a-half” – 1.5
times their hourly wage – for overtime hours worked), commission workers (who receive LE 250 plus
5.7% of their gross weekly sales), or pieceworkers (who receive a fixed amount of money per item
for each of the items they produce – each pieceworker in this company works on only one type of
item). Write a modular program to compute the weekly pay for each employee. You do not know the
number of employees in advance. Each type of employee has its own pay code: Managers have
paycode 1, hourly workers have code 2, commission workers have code 3 and pieceworkers have
code 4. Use a switch to compute each employee’s pay according to that employee’s paycode. Within
the switch, prompt the user (i.e., the payroll clerk) to enter the appropriate facts your program needs
to calculate each employee’s pay according to that employee’s paycode.
Question 6
Write a program that takes ten integers as input. The program places the even integers into an array
called evenList, the odd integers into an array called oddList, and the negative integers into an array
called negativeList. The program displays the contents of the three arrays – in a tabular form – after
all of the integers have been entered.
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Question 7
Write a program fragment that uses only two nested loops (the number of loops should not exceed 2)
to produce the following output:
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1
1
1
1
1
1
1
1
1
1
1
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1
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Question 8
Write a complete C++ program that has a main function, a GetThreeNumbers function, and a
DescSort function. The main function calls the GetThreeNumbers function, which asks the user
for three positive integers. Then the program sends the three integers to DescSortt, which arranges
the three integers in a descending order. The main function will then print out the three sorted
integers.
Incorporate a loop in the main function so that the user can keep entering three integers as long as he
or she desires. Your program should prompt the user how to stop the program.
Question 9
An integer is divisible by 9 if the sum of its digits is divisible by 9. Write a program that prompts the
user to input an integer. The program should then output the number and a message stating whether
the number is divisible by 9. It does so using the given rule.
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