// L-35 MCS 360 Fri 12 Nov 2010 : mcs360_btree.tc

/* This file defines the members of the templated class B_Tree
   in the namespace mcs360_btree. */

namespace mcs360_btree
{
   template < typename Item_Type, int numbchil >
   B_Tree<Item_Type,numbchil>::B_Tree()
   {
      root = NULL;
   }

   template < typename Item_Type, int numbchil >
   B_Tree<Item_Type,numbchil>::B_Tree( int n, Item_Type *a ) 
   {
      root = new Node;
      root->size = n;
      for(int i=0; i<n; i++)
         root->data[i] = a[i];
   }

   template < typename Item_Type, int numbchil >
   B_Tree<Item_Type,numbchil>::B_Tree( int n, Item_Type *a,
      B_Tree<Item_Type,numbchil> *c )
   {
      root = new Node;
      root->size = n;
      for(int i=0; i<n; i++)
      {
         root->data[i] = a[i];
         root->child[i] = c[i].root;
      }
      root->child[n] = c[n].root;
   }

   template < typename Item_Type, int numbchil >
   int B_Tree<Item_Type,numbchil>::get_size() 
   {
      return root->size;
   }

   template < typename Item_Type, int numbchil >
   Item_Type* B_Tree<Item_Type,numbchil>::get_data() 
   {
      return root->data;
   }

   template < typename Item_Type, int numbchil >
   bool B_Tree<Item_Type,numbchil>::is_null_child(int k) const
   {
      return (root->child[k] == NULL);
   }

   template < typename Item_Type, int numbchil >
   B_Tree<Item_Type,numbchil> B_Tree<Item_Type,numbchil>::get_child(int k) const
   {
      B_Tree<Item_Type,numbchil> b;
      b.root = root->child[k];
      return b;
   }

   template < typename Item_Type, int numbchil >
   int B_Tree<Item_Type,numbchil>::binary_search
      (int first, int last, Item_Type i)
   {
      if(first == last)
         return first;
      else
      {
         int middle = (first + last)/2;

         if(i == root->data[middle])
            return middle;
         else if(i < root->data[middle])
            return binary_search(first,middle,i);
         else
            return binary_search(middle+1,last,i);
      }
   }

   template < typename Item_Type, int numbchil >
   int B_Tree<Item_Type,numbchil>::search ( Item_Type i )
   {
      int L = root->size-1;
      if(i > root->data[L])
         return L+1;
      else
         return this->binary_search(0,L,i);
   }
}