typedef struct HashTabRep {
   int  N;       // size of array
   Item **items; // array of (Item *)
} HashTabRep;

HashTable newHashTable(int N)
{
   HashTable new = malloc(sizeof(HashTabRep));
   new->items = malloc(N*sizeof(Item *));
   new->N = N;
   for (int i = 0; i < N; i++)
      { new->items[i] = NULL; }
   return new;
}