simpleGradebook.c

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

/* define a more readable value for how many grades we want */
#define NUM_GRADES 10

/* weird way of making swap in C */
#define swap(type, i, j) {type t = i; i = j; j = t;}

int main(int argc, char** argv){
    int i,j,ret;
    size_t read_b,size; // C is weird, ignore
    int grades[10];
    char buf[10]; // ignore

    /* this is a String in C, logistics arent really relevant */
    char *s_name;
    s_name = (char*) malloc( sizeof(char) * 100 );

    fprintf(stdout, "Please enter the student's name.\n"); // print message to user
    /* read entire line from terminal and store it somewhere */
    read_b = getline(&s_name, &size, stdin);

    fprintf(stdout, "Please enter 10 grades.\n"); // print message to user
    /* read 10 integers from user input to terminal */
    for( i = 0; i < NUM_GRADES; ++i ) grades[i] = 0;
    for( i = 0; i < NUM_GRADES; ++i ){
        /*
         * reads an input in terminal
         * then converts it to an integer and saves it
         * NOTE: This is a poor example of how to do this right
         *      it's just simple/fast.
         */
        ret = scanf( "%s", buf );
        grades[i] = atoi( buf );
        if( grades[i] < 0 || grades[i] > 100 ) exit(1); // error
        if( ret == 0 || ret == EOF ) exit(1); // error
    } // end for

    for( i = 2; i < NUM_GRADES; ++i ){
    //  sum += grades[i];
        printf("Grades[%d] = %d\n", i, grades[i]);
    }

    /* bubble sort */
    int flag;
    for( ;; ){ // infinite loop
        flag = 0;
        for( j = 1; j < NUM_GRADES; ++j ){
            /* "bubbleup" */
            if( grades[j-1] > grades[j] ){
                swap( int, grades[j-1], grades[j] );
                flag = 1;
            } // end if
        } // end j for
        if( flag == 0 ) break; // if flag is false eg 0 stop looping
    } // end i for

    int sum;
    sum = 0;
    /*
     * calculate the sum
     * start at index 2 because the array is in
     * increasing order thus grades[0] and grades[1]
     * are the lowest and the dropped grades
     */
    for( i = 2; i < NUM_GRADES; ++i ){
        sum += grades[i];
        printf("Grades[%d] = %d\n", i, grades[i]);
    }

    /*
     * output the name, sum and average of scores
     *
     * %s tells the function to print that string (s_name)
     * %d tells the function to print that integer (sum)
     */
    fprintf(stdout, "Student name: %s\nTotal of top 8 scores: %d\nAverage: %d\n", s_name, sum, sum/8);

    /* C stuff */
    exit(1);
}