Question

Write a program in C language that reads scores and id numbers from a file, finds the average score, and assigns each student a grade based on the following rules:

Each score > average + 20 gets an A
Each score between average + 10 and average + 20 gets a B
Each score between average - 10 and average + 10 gets a C
Each score between average - 20 and average - 10 gets a D
Each score < average - 20 gets an F.

The main program has been completed. I need to convert each stub to a working module. Here are the remaining stubs:

double findAverage(double s[], int num)
{
//Another stub.  Re-write this so that it finds the average of the
//doubles stored in the first num locations of s[], and returns
//that average
  printf("You successfully called findAverage.\n");
  return 50.0;
}

void assignGrades(double s[], char g[], int num, double average) 
{
//Yet another stub.  Re-write it so that it fills the array g[] with
//grades using the rules defined at the start of this page
  printf("You successfully called assignGrades.\n");
}


void  printSummary(double s[], int ids[], char g[], int numScores, double average) 
{
//The last stub.  Re write it so that it prints a table.  The first
//column should be id numbers. The second column should be the corresponding
//scores.  The third column the amount by which the score differs from the
//average.  The final column should be the corresponding letter grade.
  printf("You successfully called printSummary.\n");
}

Answer 1

Below is the C code I hope that i have provided sufficient comments for your better understanding Note that I have done proper indentation but this code is automatically left alligned on this interface

double findAverage(double s[], int num)
{
int i;
double sum = 0.0, average;
for(i = 0; i < num; ++i)
{
sum += s[i]; //Add every element
}
average = sum / num;
printf("You successfully called findAverage.\n");
return average;
}
void assignGrades(double s[], char g[], int num, double average)
{
int i;
for(i = 0; i < num; ++i)
{
//Assign grades as specified
if(s[i]>average+20)
g[i]='A';
else if(s[i]>average+10)
g[i]='B';
else if(s[i]>average-10)
g[i]='C';
else if(s[i]>average-20)
g[i]='D';
else
g[i]='F';
}
printf("You successfully called assignGrades.\n");
}
void printSummary(double s[], int ids[], char g[], int numScores, double average)
{
int i;
for(i=0;i<numScores;i++)
{
printf("%d\t%lf\t%lf\t%c\n",ids[i],s[i],s[i]-average,g[i]);
}
printf("You successfully called printSummary.\n");
}

I have tried to explain it in very simple language and I hope that i have answered your question satisfactorily.Leave doubts in comment section if any