pointers.c

#include <stdio.h>
#include <math.h>

void avg_pbr(int a, int b, int *r);
int avg(int b, int a);

int main()
{

    int *result;
    int res;
    int res2;


    // Pass the values
    res = avg(5, 15);
    printf("Norm: %d\n", res);

    // Pass a pointer
    avg_pbr(15, 25, result);
    printf("Address: %p\n", result);
    printf("By ptr: %d\n", *result);

    // Pass by reference
    avg_pbr(25, 35, &res2);
    printf("Address: %p\n", &res2);
    printf("By ref: %d\n", res2);

        
    return 0;
}

int avg(int a, int b)
{
    return (a+b)/2;
}

void avg_pbr(int a, int b, int *r) 
{
    *r = (a+b)/2;
}