middle
The Task
A function that returns the middle number of the parameters.
The Program
<![CDATA[
/* File: middle.c
Author: Sue Bogar
Date Written: 3/17/99
Section: 0101
E-Mail: bogar@cs.umbc.edu
This program uses a function that returns
the middle value of three integers.
*/
#include <stdio.h>
/* Function Prototype */
int Middle(int, int, int) ;
int main()
{
int n1, n2, n3, middle ;
/* Get 3 integers from the user */
printf("Enter first number: ") ;
scanf ("%d", &n1) ;
printf("Enter second number: ") ;
scanf ("%d", &n2) ;
printf("Enter third number: ") ;
scanf ("%d", &n3) ;
/* Find & print the middle value */
middle = Middle(n1, n2, n3) ;
printf("The middle number is: %d\n", middle) ;
return 0;
}
/* Function: Middle
*
* Middle returns the middle value of the
* 3 integers passed into it as arguments
*
* Inputs: 3 integers
* Output: the middle value of the values passed in
*/
int Middle(int a, int b, int c)
{
int middle;
/* a is the middle */
if (b >= a && a >= c)
{
middle = a ;
}
else if (c >= a && a >= b)
{
middle = a ;
}
/* b is the middle */
else if (a >= b && b >= c)
{
middle = b ;
}
else if (c >= b && b >= a)
{
middle = b ;
}
/* c is the middle */
else if (b >= c && c >= a)
{
middle = c ;
}
/* a >= c && c >= b is the only
remaining possible combination */
else
{
middle = c ;
}
return middle ;
}
]]>
The Sample Run
<![CDATA[
linux3[80] % gcc -Wall -ansi middle.c
linux3[81] % a.out
Enter first number: 7
Enter second number: 9
Enter third number: 2
The middle number is: 7
linux3[82] % !a
a.out
Enter first number: 7
Enter second number: 2
Enter third number: 9
The middle number is: 7
linux3[83] % !a
a.out
Enter first number: 5
Enter second number: 4
Enter third number: 3
The middle number is: 4
linux3[84] % !a
a.out
Enter first number: 3
Enter second number: 4
Enter third number: 5
The middle number is: 4
linux3[85] % !a
a.out
Enter first number: 7
Enter second number: 9
Enter third number: 8
The middle number is: 8
linux3[86] % !a
a.out
Enter first number: 9
Enter second number: 7
Enter third number: 8
The middle number is: 8
linux3[87] % !a
a.out
Enter first number: 3
Enter second number: 3
Enter third number: 3
The middle number is: 3
linux3[88] %
]]>
Exhaustive Testing
Have we tried every possibility in our testing ?
What have we missed ?