Thread: Dynamic Allocating Array and Function Call

Clearly I'm not doing this right, what am I missing?

Code:

/* printing the average grade for every student in every class.
printing out the average grade per class; printing out the average grade per student over all
classes. Your college administration wants this task accomplished by a program which allocates
memory for the array to hold the student grades in the classes. Then, each printing must be
accomplished by a separate function with the array or portions thereof passed as parameters.   */


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

#define NUMBER_OF_STUDENTS  11 //globals for array variables
#define NUMBER_OF_CLASSES   4
#define NUMBER_OF_GRADES    5

float gradeAve(int ***c);
void freeArray(int ***a);

int main()
{
int i, j, student, class, grade;

   int*** array;
   
   array=malloc(NUMBER_OF_STUDENTS*sizeof(int**));
   
   for (i=0; i<NUMBER_OF_STUDENTS; i++)
   {
   
      array[i]=malloc(NUMBER_OF_CLASSES*sizeof(int*));
      
        for (j=0;i<NUMBER_OF_CLASSES;j++)
        {
        
            array[i][j]=malloc(NUMBER_OF_GRADES*sizeof(int));} }
            
for(student=0; student<NUMBER_OF_STUDENTS; student++)
    {//for loop for populating 3 dimensional array
        for(class=0;class<NUMBER_OF_CLASSES;class++)
            {
    
        for(grade=0; grade<NUMBER_OF_GRADES; grade++)
            {
            if(grade==0){
                printf("Enter in the grade for student %d in subject %d:\n", student+1, class+1);
                scanf("%d", &array[student][class][grade]);
            }else
                scanf("%d",&array[student][class][grade]);
}
}
}
            
            

printf("Average of all Grades: %.2f\n", gradeAve(array));
freeArray(array);
}

float gradeAve(int ***c)
{
  float sum=0;
    int grade;//local variables

        for(grade=0; grade<NUMBER_OF_GRADES; grade++)
        {
            sum+=c[NUMBER_OF_STUDENTS][NUMBER_OF_CLASSES][NUMBER_OF_GRADES];//only takes sum of the grades and divides by number of grades
        }
    
    return (sum/NUMBER_OF_GRADES);

}

void freeArray(int ***a) {
    int i, j;
    for (j=0; j< NUMBER_OF_CLASSES; ++j)
        free(a[j]);
    for (i = 0; i < NUMBER_OF_GRADES; ++i) {
        free(a[j][i]);
    }
    free(a);
}

You do not free your memory.

Also, do not cast malloc

Do not cast it. Just let it as it is.
You have something like this

Code:

... = (int)malloc...

Do it like this

Code:

... = malloc...

But this is not why your code crashes. Neither is the fact that you didn't free the memory.

Check here

Code:

array[i]=(int**)malloc(NUMBER_OF_CLASSES*sizeof(int*));{
        for (j=0;i<NUMBER_OF_GRADES;j++)

Change that to this

Code:

 array[i]=malloc(NUMBER_OF_CLASSES*sizeof(int*));
 
        for (j=0;j<NUMBER_OF_CLASSES;j++)
        {

The Indent style would tell you the truth by itself

Well, post your updated code please

Still on line 31 you have i instead of j!!!

Also in the function that you calculate the average, you get out of bounds!

You should go through every cell. You can do that the same way you filled them up in main

The free function is also wrong, but first fix the others and then we talk about the free. I would suggest you to comment the function or not to call it yet