Calculate the section average give the breakdown of grades.
The Method
Have an array called scores, whose size is the maximum section size
Have an array called grades, that will hold the number of A's, B's, etc.
Let the index match the quality points for that grade.
Initialize the elements of both arrays to 0
Get number of students in the section from user
Get a score at a time from the user until done
Store each grade in the scores array, and keep a running total.
Increment the corresponding grade array element.
Calculate & print average
Print chart - frequency of grades
The Program
/*****************************************
** File: grades.c
** Author: S. Bogar
** Date: 8/25/99
** Section: 101
** EMail: bogar@cs.umbc.edu
**
** This program calculates the section average
** and gives a breakdown of the grades (e.g.
** 6 As, 10 Bs ...) for a section of MAX or
** less students.
*****************************************/
#include <stdio.h>
#define MAX 75
int main ( )
{
int scores[MAX], grades[5], i, students ;
float total, average;
total = 0;
/* Initialize grades array to zeros */
for (i = 0; i < 5 ; i++)
{
grades[i] = 0 ;
}
/* Initialize scores array to zeros */
for (i = 0; i < MAX ; i++)
{
scores[i] = 0 ;
}
/* Prompt for # of students in the section */
printf ("Enter # of students in this section: ");
scanf ("%d", &students);
/* Catch errors in section size */
while (students > MAX || students < 1)
{
printf ("Invalid # of students\n");
printf ("Section size is 1 - %d\n", MAX);
printf ("Enter # of students in this section: ");
scanf ("%d", &students);
}
/* Get scores from user */
for (i = 0; i < students; i++)
{
printf ("Enter score for student %d: ", i + 1);
scanf ("%d", &scores[i]);
/* Accumulate total */
total += scores[i];
/* Increment appropriate grade frequency*/
switch ( scores[i] / 10 )
{
case 10:
case 9: grades[4]++;
break;
case 8: grades[3]++;
break;
case 7: grades[2]++;
break;
case 6: grades[1]++;
break;
case 5:
case 4:
case 3:
case 2:
case 1:
case 0: grades[0]++;
break;
default: printf ("That's an invalid grade\n");
}
}
/* Print out results */
average = total / students;
printf ("\n\nThe section average is %.3f\n\n",
average);
printf ("There were : %5d A's\n", grades[4]);
printf (" %5d B's\n", grades[3]);
printf (" %5d C's\n", grades[2]);
printf (" %5d D's\n", grades[1]);
printf (" %5d F's\n\n", grades[0]);
return 0;
}
The Sample Run
linux1[77] % gcc -Wall -ansi grades.c
linux1[78] % a.out
Enter # of students in this section: 10
Enter score for student 1: 83
Enter score for student 2: 77
Enter score for student 3: 101
Enter score for student 4: 68
Enter score for student 5: 59
Enter score for student 6: 8
Enter score for student 7: 75
Enter score for student 8: 90
Enter score for student 9: 88
Enter score for student 10: 79
The section average is 72.800
There were : 2 A's
2 B's
3 C's
1 D's
2 F's
linux1[79] %