verilator/src/V3TSP.h

56 lines
1.9 KiB
C++

// -*- mode: C++; c-file-style: "cc-mode" -*-
//*************************************************************************
// DESCRIPTION: Verilator: Implementation of Christofides' algorithm to
// approximate the solution to the traveling salesman problem.
//
// Code available from: https://verilator.org
//
//*************************************************************************
//
// Copyright 2003-2021 by Wilson Snyder. This program is free software; you
// can redistribute it and/or modify it under the terms of either the GNU
// Lesser General Public License Version 3 or the Perl Artistic License
// Version 2.0.
// SPDX-License-Identifier: LGPL-3.0-only OR Artistic-2.0
//
//*************************************************************************
#ifndef VERILATOR_V3TSP_H_
#define VERILATOR_V3TSP_H_
#include "config_build.h"
#include "verilatedos.h"
#include "V3Error.h"
namespace V3TSP {
// Perform a "Traveling Salesman Problem" optimizing sort
// on any type you like -- so long as inherits from TspStateBase.
class TspStateBase VL_NOT_FINAL {
public:
// This is the cost function that the TSP sort will minimize.
// All costs in V3TSP are int, chosen to match the type of
// V3GraphEdge::weight() which will reflect each edge's cost.
virtual int cost(const TspStateBase* otherp) const = 0;
// This operator< must place a meaningless, arbitrary, but
// stable order on all TspStateBase's. It's used only to
// key maps so that iteration is stable, without relying
// on pointer values that could lead to nondeterminism.
virtual bool operator<(const TspStateBase& otherp) const = 0;
virtual ~TspStateBase() = default;
};
using StateVec = std::vector<const TspStateBase*>;
// Given an unsorted set of TspState's, sort them to minimize
// the transition cost for walking the sorted list.
void tspSort(const StateVec& states, StateVec* resultp);
void selfTest();
} // namespace V3TSP
#endif // Guard