typedef struct HashTabRep {
   Item *items; // array of Items
   int  nslots; // # elements in array
   int  nitems; // # items stored in HashTable
   int  nhash2; // second hash mod
} HashTabRep;

#define hash2(k,N2) (((k)%N2)+1)

HashTable newHashTable(int N)
{
   HashTabRep *new = malloc(sizeof(HashTabRep));
   assert(new != NULL);
   new->items = malloc(N*sizeof(Item));
   assert(new->items != NULL);
   for (int i = 0; i < N; i++)
      new->items[i] = NoItem;
   new->nslots = N; new->nitems = 0;
   new->nhash2 = findSuitablePrime(N);
   return new;
}