C: Why doesn't this code work? - c

Question

Need help with this code it should return c[] with the number's of a[] % b[] = 0 but it doesn't work.
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int *divide(int a[], int a_size, int b[], int b_size)
{
int i = 0, j = 0, k = 0, counter = 0, *c;
c = (int*)malloc(b_size * sizeof(int));
for (i = 0; i < b_size; i++)
{
for (j = 0; j < a_size; j++)
{
if (a[j] % b[i] == 0)
counter++;
}
c[k] = counter;
k++;
counter = 0;
}
for (int t = 0; t < b_size; t++)
{
printf("%d ", c[t]);
}
printf("\n");
}
main ()
{
int *a, *b, a_size, b_size;
printf("Enter size of a:\n");
scanf ("%d", &a_size);
a = (int*)malloc(a_size * sizeof(int));
printf("\nEnter size of b:\n");
scanf("%d", &b_size);
b = (int*)malloc(b_size * sizeof(int));
printf("\nEnter elements of a:\n");
for (int i = 0; i < a_size; i++)
{
scanf("%d", &a[i]);
}
printf("\nEnter elements of b:\n");
for (int j = 0; j < b_size; j++)
{
scanf("%d", &b[j]);
}
divide(&a, a_size, &b, b_size);
}

Answer 1

There was some errors in your code.
You want your fonction *divide(...) to return a new array containing the operation a[i] % b[i], but your function doesn't return anything, so you have to return it. It seems more logical to print the new array in the main, than in the function while doing it.
When you pass the variables to your function be careful to pass int*, not int **.
Here is a sample of code which works (you didn't say what to do if a_size and b_size were different so I assume we only use the smallest size and don't treat the number after) :
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
int *divide(int a[], int a_size, int b[], int b_size)
{
int i = 0, stop, *c;
if (b_size <= a_size)
{
c = (int*)malloc(b_size * sizeof(int));
stop = b_size;
}
else
{
c = (int*)malloc(a_size * sizeof(int));
stop = a_size;
}
while (i < stop)
{
c[i] = a[i] % b[i];
i++;
}
return (c);
}
int main ()
{
int *a, *b, a_size, b_size;
int *result = NULL;
int stop;
int i = 0;
printf("Enter size of a:\n");
scanf ("%d", &a_size);
a = (int*)malloc(a_size * sizeof(int));
printf("\nEnter size of b:\n");
scanf("%d", &b_size);
b = (int*)malloc(b_size * sizeof(int));
printf("\nEnter elements of a:\n");
for (int i = 0; i < a_size; i++)
{
scanf("%d", &a[i]);
}
printf("\nEnter elements of b:\n");
for (int j = 0; j < b_size; j++)
{
scanf("%d", &b[j]);
}
result = divide(a, a_size, b, b_size); //not &a neither &b because it would be a char** instead of a char*
if (a_size < b_size)
stop = a_size;
else
stop = b_size;
while (i < stop)
{
printf("%d ", result[i]);
i++;
}
return 0;
}