Description
Problem A
A.1 Specification
Write a C program that contains two functions, one to input two non-empty strings and the other to
compare them. The comparison returns an integer that indicates the first position (array index) where
the two strings differ.
A.2 Implementation
• The program to be submitted is named lab4a.c. Use the given template lab4a.c and fill in
your code. Submit only file lab4a.c.
• The first function to be implemented is myStrInput(). See file lab4a.c for its specification.
Use getchar and a loop to read a line of characters, and store the input characters into the array.
The loop terminates when a new line character ‘\n’ is entered. The new line character ‘\n’ is NOT
part of the line (i.e., discard the new line character ‘\n’).
• The second function to be implemented is myStrCmp(). See file lab4a.c for its specification.
The function returns an integer that indicates the first position (array index) where the two strings
differ. Consider the following two special cases:
o Two strings are equal. In that case the return value is ─1.
o One string is a substring of the other (e.g., CSE2031 and CSE2031E3.0). In that case, the
return value is the length of the shorter string (i.e., the index of the null character in the
shorter string).
• In both functions, do not use array indexing such as s[i]. Use only pointers and address
arithmetic to manipulate the array elements. If you use array indexing in your code, your program
will not be marked and given zero point. Hint: Write and test your program using array indexing
first, then “translate” array accesses to pointers.
• Do not modify the function definitions in file lab4a.c.
A.3 Sample Inputs/Outputs
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Problem B
B.1 Specification
Write a C program to input a line of characters in the form of a floating-point number, convert the line
of characters into an actual floating-point number, and display on the standard output the floating-point
number.
B.2 Implementation
• The program is named lab4b.c. Use the given template lab4b.c and fill in your code.
• You are given an array of characters of size MAX_SIZE where MAX_SIZE = 100. The array is
named my_strg.
• Use getchar and a loop to read a line of characters, and store the input characters into array
my_strg. The loop terminates when a new line character ‘\n’ is entered. The new line character
‘\n’ is NOT part of the line (i.e., discard the new line character ‘\n’).
• The input line contains only characters ‘0’ to ‘9’ and the dot character ‘.’ in the form of a valid
positive floating point number of the following format: [integer part] . [fractional part]
• Convert the input line of characters to a double floating-point number, which is stored in variable
my_number.
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• Display on the standard output the double floating-point number my_number using the printf
statement as follows:
printf( “%.2f\n”, my_number );
• Assume that the input line of characters represents a valid floating point number of the form
[integer part] . [fractional part]
B.3 Sample Inputs/Outputs
indigo 360 % lab4b
24.5
24.50
indigo 361 % lab4b
76.2421
76.24
indigo 362 % lab4b
100.0
100.00
indigo 363 % lab4b
0.255
0.26
indigo 364 % lab4b
12.9999999999
13.00
indigo 365 % lab4b
1.00000000099
1.00
indigo 366 % lab4b
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Problem C
C.1 Specification
Write a C program to input an integer k. Compute 10k and store the result in a double variable. Display
the result on the standard output using printf.
C.2 Implementation
• The program is named lab4c.c. Use the given template lab4c.c and fill in your code.
• Assume that the input integer k is small enough so that 10k can be stored in a double variable
named my_double.
• Display on the standard output the result using the printf statement as follows:
printf( “%.15lf\n”, my_double );
B.3 Sample Inputs/Outputs
EECS 2031 Page 5 of 5
Common Notes
All submitted files should contain the following header:
/***************************************
* EECS2031 – Lab 4
* Filename: Name of file
* Author: Last name, first name
* Email: Your preferred email address
* EECS login ID: Your EECS login ID
****************************************/
In addition, all programs should follow the following guidelines:
• Include the stdio.h library in the header of your .c files.
• Use printf to print text and outputs according to the required formats.
• End each output result with a new line character ‘\n’.
• Do not use any C library functions except getchar(), putchar(), scanf() and
printf().
• Assume that all inputs are valid (no error checking is required on inputs).
