47 lines
1.5 KiB
C++
47 lines
1.5 KiB
C++
/*
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* Copyright (C) 2005 Maarten Keijzer
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of version 2 of the GNU General Public License as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#ifndef NODESELECTOR_H
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#define NODESELECTOR_H
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class Sym;
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/** Base class for selecting nodes */
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class NodeSelector {
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public:
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virtual unsigned select_node(Sym sym) const = 0;
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};
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/** Select nodes uniformly */
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class RandomNodeSelector : public NodeSelector {
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public:
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unsigned select_node(Sym sym) const;
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};
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/** A node selector that does a specified number of rounds ignoring terminals */
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class BiasedNodeSelector : public NodeSelector {
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public:
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unsigned nRounds;
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BiasedNodeSelector() : nRounds(3) {} // 3: for binary trees 87.5% chance of selecting an internal node
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BiasedNodeSelector(unsigned n) : nRounds(n) {}
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unsigned select_node(Sym sym) const;
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};
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#endif
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