Question

Write a C program that allows a user to enter up to 30 student id’s and 3 grades per student. It will then compute and display a report of the students averages, and then a statement of the class average for those grades. The following is a sample run that demonstrates what your program should look like:

Please enter your school name: Cape Tech

Welcome to the Cape Tech Grade Calculator

Enter the number of students to process (0 - 30): 33

*** Invalid number of students entered. ***

Enter the number of students to process (0 - 30): 3

Enter the ID Number for student #1(0-9999): 1234

Now enter the 3 grades to be averaged. Enter grade #1: 77

Enter grade #2: 88 Enter grade #3: 99

Enter the ID Number for student #2(0-9999): 23456

Bad ID Number, please re-enter Enter the ID

Number for student #2(0-9999): 3456

Now enter the 3 grades to be averaged.

Enter grade #1: 55 Enter grade #2: 777

*** Invalid entry. Grade must be from 0 to 100. ***

Enter grade #2: 77

Enter grade #3: 62

Enter the ID Number for student #3(0-9999): 034

Now enter the 3 grades to be averaged.

Enter grade #1: 44

Enter grade #2: 77

Enter grade #3: 98

Grade Report for Cape Tech ID No. Avg.

Grade 1234 88 B+ 3456 65 D 0034 73 C

The class average of the 3 students is 75. This program needs to use arrays ad these variables:

int number_of_students; /* user decides number of students */

int grade1, grade2, grade3; /* holds 3 integer grades */

int id[30]={0}; /* holds up to 30 integer student ids */

int average[30]; /* will contain the averages rounded off */

char my_name[20] = "CCCC"; /* array of up to 20 characters for school*/

int class_total = 0; /* accumulator int class_average; /* will contain the averages rounded off */

int x; /* loop control variable */

int sum = 0; /* initialize sum to zero.*/

char c; /* for buffer clearing *

Answer 1

Program

#include<stdio.h>
int main()
{
   int number_of_students; /* user decides number of students */
   int grade1, grade2, grade3; /* holds 3 integer grades */
   int id[30]={0}; /* holds up to 30 integer student ids */
   int average[30]; /* will contain the averages rounded off */
   char my_name[20] = "CCCC"; /* array of up to 20 characters for school*/
   int class_total = 0; /* accumulator */
   int class_average; /* will contain the averages rounded off */
   int x; /* loop control variable */
   int sum = 0; /* initialize sum to zero.*/
   char c; /* for buffer clearing */
   char grade[30];

   printf("Please enter your school name:");
   gets(my_name);
   printf("Welcome to the %s Grade Calculator",my_name);
   printf("\nEnter the number of students to process (0 - 30):");
   scanf("%d",&number_of_students);
   while(number_of_students<0||number_of_students>30)
   {
   printf("\n*** Invalid number of students entered. ***");
   printf("\nEnter the number of students to process (0 - 30):");
   scanf("%d",&number_of_students);
  
   }
   for(x=0;x<number_of_students;x++)
   {
   printf("Enter the ID Number for student #%d(0-9999):",(x+1));
   scanf("%d",&id[x]);
   while(id[x]<0||id[x]>9999)
   {
   printf("\nBad ID Number, please re-enter ID");
   printf("\nEnter the ID Number for student #%d(0-9999):",(x+1));
   scanf("%d",&id[x]);
   }
   printf("Now enter the 3 grades to be averaged.");
   printf("\nEnter grade #1: ");
   scanf("%d",&grade1);
   while(grade1<0||grade1>100)
   {
   printf("\n*** Invalid entry. Grade must be from 0 to 100. ***");
   printf("\nEnter grade #1: ");
   scanf("%d",&grade1);
   }
   printf("Enter grade #2: ");
   scanf("%d",&grade2);
   while(grade2<0||grade2>100)
   {
   printf("\n*** Invalid entry. Grade must be from 0 to 100. ***");
   printf("\nEnter grade #2: ");
   scanf("%d",&grade2);
   }
   printf("Enter grade #3: ");
   scanf("%d",&grade3);
   while(grade3<0||grade3>100)
   {
   printf("\n*** Invalid entry. Grade must be from 0 to 100. ***");
   printf("\nEnter grade #3: ");
   scanf("%d",&grade3);
   }
   sum=grade1+grade2+grade3;
   average[x]=sum/3;
   class_total+=sum;
   if (average[x]>=90)
        {  
            grade[x]='A';
         
        }
        else if (average[x]>=80)
        {
            grade[x]='B';
          
        }
        else if (average[x]>=70)
        {
            grade[x]='C';
          
        }
        else if (average[x]>=60)
        {
            grade[x]='D';
          
        }
        else
        {
            grade[x]='F';
          
        }
   }
   printf("Grade Report for %s ",my_name);
   printf("\nIDNo. \tAvg.\tGrade\n");
   for(x=0;x<number_of_students;x++)
   {
   printf("%d\t%d\t%c\n",id[x],average[x],grade[x]);
   }
   class_average=class_total/(number_of_students*3);
   printf("\nThe class average of the %d students is %d\n",number_of_students,class_average);
   return 0;
}

Output

Please enter your school name:Cape Tech
Welcome to the Cape Tech Grade Calculator
Enter the number of students to process (0 - 30):33

*** Invalid number of students entered. ***
Enter the number of students to process (0 - 30):3
Enter the ID Number for student #1(0-9999):1234
Now enter the 3 grades to be averaged.
Enter grade #1: 77
Enter grade #2: 88
Enter grade #3: 99
Enter the ID Number for student #2(0-9999):23456

Bad ID Number, please re-enter ID
Enter the ID Number for student #2(0-9999):3456
Now enter the 3 grades to be averaged.
Enter grade #1: 55
Enter grade #2: 777

*** Invalid entry. Grade must be from 0 to 100. ***
Enter grade #2: 77
Enter grade #3: 62
Enter the ID Number for student #3(0-9999):034
Now enter the 3 grades to be averaged.
Enter grade #1: 44
Enter grade #2: 77
Enter grade #3: 98

Grade Report for Cape Tech

IDNo.    Avg.   Grade
1234   88   B
3456   64   D
34   73   C

The class average of the 3 students is 75