a8.c

/*
        Name: Kevin C. Bell, Nicholas J. Bravata, Thomas J. Jury        Class: CPS 360
        Section: 22362460                                               Assignment: 08
        Due: April 3, 2019                                              Started: April 29, 2019
        Credit: 10 points.
        
        Problem: Write a program that will read in exam1, exam2, exam3 scores of students of a class
        from stdin. Then compute the integer mean of scores of a student. Finally it will print the
        lowest mean, highest mean, and mean of the mean-scores of the class. The program will use a
        1-dimensional array (memory view) to simulate a 2-dimensional array (programming language view).
        
        Solution: When the program starts it first obtains from stdin the number of students. This number
        is then used to make an array for test scores using malloc(), the size of the array is 3 * nstudents
        because each student can have 3 exams. After the array is made it is then passed to getdata(), once
        there test scores are read in from stdin and stored into our scores array. The array is then passed
        to procdata() along with nstudents, and pointers highmean, lowmean, meanofmean. This method will 
        produce the mean of each student and calculate the meanofmean. The student with the lowest mean will
        have their mean stored in lowmean and the student with the highest mean will be stored in highmean.
        procdata1() will then do the exact same thing as procdata() but it is coded in assembly giving you
        the exact same outcome. Finally the results of both procdata and procdata1() will be printed using the 
        method printresults(). The data will be printed with a meaningful message and label. Before ending the
        program uses free() on our scores then ends with an EXIT_SUCCESS.
        
        Data-structure used: A one-dimensional array of integers to store student test scores.
        
        Accessing functions for the data structure: Standard C functions for accessing arrays and 
        malloc() and free() to allocate the memory for the student's test scores array.
        
        Errors handled: None.
        
        Limitations: This program will only take in a format of number of students and each student 3 test afterwards
        anything other than that will make the program not work. Anymore test or more students other than the
        specifed prior will not be counted.
        
        Acknowledgment: We wrote the program together but we had a lot of help from our classmates throughout the 
        making of it.
*/


#include <stdlib.h>
#include <stdio.h>

int main() 
{
   int getcount();
   int getdata(int data[], int nstudents);
   void printresults(char *label, int mlow, int mhigh, int mmean);
   void procdata(int tscores[], int nstudents, int *lowmean, int *highmean, int *meanofmean);
   extern void procdata1(int tscores[], int nstudents, int *lowmean, int *highmean, int *meanofmean);

   int highmean, lowmean,  meanofmean, num = getcount(), *scores;

   scores = (int *)malloc(sizeof(int) * (num * 3));
   num = getdata(scores, num);

   procdata(scores, num, &lowmean, &highmean, &meanofmean);
   printresults("Procdata produced", lowmean, highmean, meanofmean);

   procdata1(scores, num, &lowmean, &highmean, &meanofmean);
   printresults("Procdata1 produced", lowmean, highmean, meanofmean);

   exit(0);
}

/* Design a module that reads in from stdin using scanf().
   The data is then scanned using scanf() then it uses the
   first number as the count and return it for it to be 
   used.
   Called by main().
*/
int getcount()
{
   int count;
   scanf("%d", &count);
   return count;
}

/* Design a module that fills an array d[] of size nstudents
   with student scores read in from stdin and returns the count
   of students actually read in from stdin. 
   Using the scanf() and '%d' 3 test scores are read in at a time
   and stored into d[] accordingly looping through the data array. 
   Once the 3 tests are entered in a running count is incremented 
   up by one while another is incremented by 3 to keep track of the
   amount of exams counted in. Once i = nstudents or scanf() returns
   a -1 for one of the tests, the running count is returned.
   Called by main().
*/
int getdata(int data[], int nstudents)
{
   int i = 0, j = 0;
   int a, b, c;
   for (i = 0; i < nstudents; i++)
   {
       scanf("%d %d %d", &a, &b, &c);
       if (a == -1 || b == -1 || c == -1) break;
       data[j] = a; data[j + 1] = b; data[j + 2] = c;
       j += 3;
   }
   return i;
}

/* Design a module that takes in an array of test scores, number of 
   students and the returns the lowest, highest, and mean of means. 
   Sum, mean and high mean are declared and initalized to 0 and low 
   mean is initalized at 100 so it is set to the first mean. Using a 
   for loop to go through each students exam scores, the average score 
   for that student's exams are stored to the mean and added to the
   overall sum. The mean is then compared to the highmean and lowmean and
   swaps are made accordingly. Nothing is returned but highmean, lowmean, 
   and meanofmean are stored at the end.
   Called by main()
*/
void procdata(int tscores[], int nstudents, int *lowmean, int *highmean, int *meanofmean)
{
   int i, sum = 0, mean = 0;
   *lowmean = 100; *highmean = 0;
   for (i = 0; i < (nstudents * 3); i += 3)
   {
       mean = (tscores[i] + tscores[i + 1] + tscores[i + 2]) / 3;
       sum += mean;
       if (*lowmean > mean) *lowmean = mean;
       if (*highmean < mean) *highmean = mean;
   }
   *meanofmean = sum / nstudents;
}

/* Design a module that takes in a char *label, int mlow, int mhigh, and 
   int mmean then prints their results. 
   Using printf() to stdout, formating conditions are used to print out 
   each mean and label with it. These ints are found by procdata() and
   procdata1().
   Called by main()
*/
void printresults(char *label, int mlow, int mhigh, int mmean)
{
   fprintf(stdout, "\n%s:\n\n", label);
   fprintf(stdout, "Lowest Mean score\t : %d\n", mlow);
   fprintf(stdout, "Highest Mean score\t : %d\n", mhigh);
   fprintf(stdout, "Mean of Means score\t : %d\n\n", mmean);
}