search( key, t )
     typekey key[K];
     tree t;

     {int bn, i, indx;
     for ( bn=1; t != NULL && !IsData(t); bn++ ) {
          indx = 0;
          for (i=0; i<K; i++) indx = 2*indx + bit(bn,key[i]);
          t = t->p[indx];
          }
     if ( t != NULL ) for (i=0; i<K && key[i]==t->k[i]; i++);
     if ( t==NULL || i < K ) notfound( key );
          else found( t );
     };