## Description

Software Tools and Systems Programming

(Computer Science 2211a)

ASSIGNMENT 2

Assignment overview

We would like students to experience command line input with C types of character, int,

and float, to understand and use C types such as char, int, and float, as well as the flow

control structures studied in class, and to use functions and recursive functions.

This assignment consists of two parts.

In part one, you are required to write a C program to perform some simple conversions.

In part two, you are to write a C program to calculate value of exponential numbers.

Part one: 70%

The goal of the exercise is to implement a simple converter, called ”converter”, which works

as follows.

(1) First, the user is asked what she/he wants to do. An integer can be entered with the

following six actions associated with different values of the integer.

• 1 for conversion between Kilometer and Mile

• 2 for conversion between Meter and Feet

• 3 for conversion between Centimetre and Inch

• 4 for conversion between Celsius and Fahrenheit

• 5 for quit

• else for repeat step (1)

(2) In case of 1, 2, 3, and 4, each action should be implemented as a function. In case of 5,

the program will terminate. For all the other values, repeat step (1).

(3) In case of 1 to 4, the program will ask the direction of the conversion. In each case, two

characters can be entered corresponding to each conversion direction.

In case of 1, the program will prompt the user for two choices and wait for a character

input

1

• K for conversion from Kilometer to Mile

• M for conversion from Mile to Kilometer

In case of 2, the program will prompt the user for two choices and wait for a character

input

• M for conversion from Meter to Feet

• F for conversion from Feet to Meter

In case of 3, the program will prompt the user for two choices and wait for a character

input

• C for conversion from Centimetre to Inch

• I for conversion from Inch to Centimetre

In case of 4, the program will prompt the user for two choices and wait for a character

input

• C for conversion from Celsius to Fahrenheit

• F for conversion from Fahrenheit to Celsius

HINT: to read a character properly, your program should handle the leading space

character, tab character, and end of line character, if any.

(4) Then the program asks for the input value, properly displays the result and returns to

Step (1).

(5) The input value should be a float number and we assume the user will always enter

valid numbers.

(6) Your program should handle non-valid single character input values for (3).

(7) Your program should prompt user and display the result to user in a descriptive manner.

(8) Your program should follow good programming styles, i.e. write clear code, choose good

variable names, use appropriate functions, make proper comments, and etc.

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Part two: 30%

The goal of this exercise is to implement an exponential number calculator, called ”exp calculator”

with recursive function.

(1) First, the user is asked for the base and the exponent. We assume that base is a positive

float number and exponent is a non-negative integer number.

(2) Then the exponential number is calculated using a recursive function in logarithmic time

in terms of the absolute value of the exponent inputted. The result is then displayed.

Hint: when n 0

a

n =

?

a

n/2 ∗ a

n/2 = (a

n/2

)

2

if n is even

a

(n−1)/2 ∗ a

(n−1)/2 ∗ a = (a

(n−1)/2

)

2 ∗ a if n is odd

(3) You can assume that the user always enter float number for the base and integer number

for the exponent. Your program should check if the input base and exponent are

positive.

(4) Your program should follow good programming styles, i.e. write clear code, choose good

variable names, use appropriate functions, make proper comments, and etc.

Testing your program

You should test your program by running it on Gaul. For part one, each case should be

tested at least once. For part two, different bases and exponents should be tested. Capture

the screen of your testing by using script command. There should be two resulting script

files, one for each part.

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