/*******************************************************************************++  LEDA 3.5+++  bb_tree.h+++  Copyright (c) 1995, 1996, 1997  by  LEDA Software GmbH+  Postfach 151101, 66041 Saarbruecken, Germany+  All rights reserved.+ *******************************************************************************/#ifndef LEDA_BB_TREE_H#define LEDA_BB_TREE_H//------------------------------------------------------------------------------//// bb_tree:  ////           BB[alpha] trees (derived from class "bin_tree")//// Stefan N"aher (1993)////------------------------------------------------------------------------------#include <LEDA/basic.h>#include <LEDA/impl/bin_tree.h> typedef bin_tree_node* bb_tree_item; // ----------------------------------------------------------------// class bb_tree// ----------------------------------------------------------------// const float alpha = 0.28;// const float d     = 0.58;// we multiply alpha, d, and all balances by 64 to make them integers  const int alpha = 18; // 0.28 * 64  const int d = 37;     // 0.58 * 64class __exportC bb_tree : public bin_tree{   int root_balance() { return 2; }  int node_balance() { return 2; }  int leaf_balance() { return 1; }  void rebal(bb_tree_item,int);  void insert_rebal(bb_tree_item);  void del_rebal(bb_tree_item, bb_tree_item);  float balance(bb_tree_item p)  { if (p->is_leaf())        return 0.5 ;    else        return float(p->child[left]->get_bal())/p->get_bal();   }public:  bb_tree() {} ~bb_tree() {}  bb_tree(const bb_tree& T) : bin_tree(T) {}  bb_tree& operator=(const bb_tree& T)   { bin_tree::operator=(T); return *this; }};#endif