Thread: Dynamic array from Function to Function

Hello, everyone.
So, my program is just counting the maximum of the array, however, I'd like to do that with the dynamic array (with pointers). Could someone explain me what am I doing wrong ? Thank you.

Code:

#include <stdio.h>
#include <stdlib.h>
void ArrayScan(int n, int *h);
void ArrayMaximum(int n, int *h, int x);
int main()
{
    int n, *array;
    int max = 0;




    printf("Write the number of random numbers: ");
    scanf("%d", &n);
    ArrayScan(n,&array);
    ArrayMaximum(n,array, max);
    free(array);
    getch();
}
void ArrayScan(int n, int *h)
{
 int i = 0;
 h = (int*)malloc(n* sizeof(int));
 for ( ; i<n; i++)
 scanf("%d", &h[i]);


}
void ArrayMaximum(int n, int *h, int x)
{
 int i=0;
 x = h[0];
 for( ;i<n;i++)
 {
  if (h[i]>x)
  x = h[i];
 };
 printf("The maximum is: %d", x);
}

Your compiler has to be warning you about an invalid call to ArrayScan() (if it's not, it's broken, and you should get a new compiler).

You're passing &array to ArrayScan(). array has type int*, so &array has type int**. However, ArrayScan() expects an int*. int** and int* are incompatible types.

Passing &array is right, because you need ArrayScan() to modify array (you need it to make array point somewhere). But that means that ArrayScan() needs to take int** instead of int*; and each time you use "h" in the function, you should be using "*h". Since h points to an int*, *h is an int*, which is to say *h is the same thing as "array" in your main function.

This is no different than passing, say, an int* to a function when it needs to modify the int. Instead, you're just passing an int** so the function can modify the int*.

Thank you very much for the response, cas. I tried to change my code (wrote int **, instead of int *, changed to *h in functions). However, it doesn't compile me.
What am i doing wrong now?

Code:

#include <stdio.h>#include <stdlib.h>
void ArrayScan(int n, int **h);
void ArrayMaximum(int n, int *h, int x);
int main()
{
    int n, *array;
    int max = 0;




    printf("Write the number of random numbers: ");
    scanf("%d", &n);
    ArrayScan(n,&array);
    ArrayMaximum(n,array, max);
    free(array);
    getch();
}
void ArrayScan(int n, int **h)
{
 int i = 0;
 h = (int*)malloc(n* sizeof(int));
 for ( ; i<n; i++)
 scanf("%d", *(h+i));
}
void ArrayMaximum(int n, int *h, int x)
{
 int i=0;
 x = *(h+i);
 for( ;i<n;i++)
 {
  if (*(h+i)>x)
  x = *(h+i);
 };
 printf("The maximum is: %d", x);
}