#include <stdio.h>
#include <stdlib.h>
int *a;

void myscanf(const char* format, int* arg) {
  *arg = rand();
}

int altInit(int size, int *pval1, int *pval2){
 1:  int i, *ptr;
 2:  a = (int *) malloc(sizeof(int) * size);
 3:  if (a == 0) {
 4:    printf("Memory exhausted.");
 5:    exit(1);
 6:  }
 7:  i = 0;
 8:  while(i < size) {
 9:    i = i + 1;
10:    if (i % 2 == 0) {
11:      ptr = pval1;
12:    } else {
13:      ptr = pval2;
14:    }
15:    a[i] = *ptr;
16:    printf("%d. iteration", i);
17:  }
18:  if (ptr == 0) ERR: ;
19:  return *ptr;
}

int main(int argc, char *argv []){
20:  int *pval = (int *) malloc(sizeof(int));
21:  if (pval == 0) {
22:    printf("Memory exhausted.");
23:    exit(1);
24:  }
25:  *pval = 0;
26:  while(*pval <= 0) {
27:    printf("Give a number greater zero: ");
28:    myscanf("%d", pval);
29:  }
30:  return altInit(*pval, pval, pval);
}