/* --------------------------------------------------------------------- 
** Figure 10.12:  Using parallel arrays.
** --------------------------------------------------------------------- 
*/
#include "tools.h"
#define MAX 16

void main( void )
{   
    int k;              /* Loop counter. */
    int n;              /* Number of students in class. */
    long id[MAX];       /* Students' ID numbers. */
    short midterm[MAX]; /* Midterm exam scores. */
    short final[MAX];   /* Final exam scores. */
    float average[MAX]; /* Average of exam scores. */
    float avg_average;  /* Average of averages. */
    float diff;         /* Student's average minus class average. */

    banner();
    printf( " Exam average = .45*midterm + .55*final.\n"
            " How many students are in the class? " );
    scanf( "%i", &n );
    if (n > MAX || n < 1) fatal( "Class size can't exceed %i.", MAX );

    printf( " At each prompt, enter an ID# and two exam scores.\n" );
    for (k = 0; k < n; ++k) {                
        printf( "\t > "); 
        scanf( "%li%hi%hi", &id[k], &midterm[k], &final[k]  );
        average[k] = .45 * midterm[k] + .55 * final[k]; 
    }

    for (avg_average = 0, k = 0; k < n; ++k) avg_average += average[k];
    avg_average /= n;
    printf( "\nAverage of the averages = %.2f\n", avg_average );

    puts( "\nID num   mid   fin   average   +/- " );
    puts( "---------------------------------- " ); 
    for (k = 0; k < n; ++k) {                
        diff = average[k] - avg_average;
        printf( "%li %5hi %5hi %8.1f %6.1f \n", 
                id[k], midterm[k], final[k], average[k], diff  );
    }
    puts( "----------------------------------" ); 

    bye();
}