int *array;
 
array = (int*)new int[size]; // re-size
delete [] array; // when you finish with it

#include <stdio.h>
#include <stdlib.h>
 
int *resize_array(int *a, size_t new_size)
{
  int *save;
 
  save = realloc(a, new_size);
  if (save == NULL) {
    fprintf(stderr, "Memory exhausted\n");
    exit(EXIT_FAILURE);
  }
 
  return save;
}
 
int main(void)
{
  int *a;
  int i = 0;
  int size;
 
  /* Allocate a new array */
  size = 5;
  a = malloc(size * sizeof *a);
  for (i = 0; i < size; i++)
    a[i] = i;
  for (i = 0; i < size; i++)
    printf("%-2d", a[i]);
  printf("\n");
 
  /* Double the size of the array */
  size *= 2;
  a = resize_array(a, size * sizeof *a);
  for (i = 0; i < size; i++)
    a[i] = i;
  for (i = 0; i < size; i++)
    printf("%-2d", a[i]);
  printf("\n");
 
  /* Destroy the array */
  free(a);
 
  return 0;
}

#include <stdio.h>
#include <stdlib.h>
 
struct node {
  int array[5];
  struct node *next;
};
 
int main(void)
{
  struct node *list = NULL;
  struct node *curr = NULL;
  int size = 0;
  int i;
 
  for (i = 0; i < 23; i++) {
    if (size % 5 == 0) {
      if (list == NULL) {
        list = malloc(sizeof *list);
        if (list == NULL)
          break;
        list->next = NULL;
        curr = list;
      }
      else {
        curr->next = malloc(sizeof *curr);
        if (curr->next == NULL)
          break;
        curr = curr->next;
        curr->next = NULL;
      }
    }
    curr->array[size++ % 5] = i;
  }
 
  for (curr = list; curr != NULL; curr = curr->next) {
    if (curr->next == NULL) {
      for (i = 0; i < size % 5; i++)
        printf("%-3d", curr->array[i]);
    }
    else {
      for (i = 0; i < 5; i++)
        printf("%-3d", curr->array[i]);
    }
  }
  printf("\n");
 
  return 0;
}