typedef struct HashTabRep {
   List *lists; // array of Lists of Items
   int  nslots; // # elements in array
   int  nitems; // # items stored in HashTable
} HashTabRep;

HashTable newHashTable(int N)
{
   HashTabRep *new = malloc(sizeof(HashTabRep));
   assert(new != NULL);
   new->lists = malloc(N*sizeof(List));
   assert(new->lists != NULL);
   for (int i = 0; i < N; i++)
      new->lists[i] = newList();
   new->nslots = N; new->nitems = 0;
   return new;
}