1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/lemon/bits/solver_bits.h Thu Dec 10 17:05:35 2009 +0100
1.3 @@ -0,0 +1,193 @@
1.4 +/* -*- mode: C++; indent-tabs-mode: nil; -*-
1.5 + *
1.6 + * This file is a part of LEMON, a generic C++ optimization library.
1.7 + *
1.8 + * Copyright (C) 2003-2008
1.9 + * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
1.10 + * (Egervary Research Group on Combinatorial Optimization, EGRES).
1.11 + *
1.12 + * Permission to use, modify and distribute this software is granted
1.13 + * provided that this copyright notice appears in all copies. For
1.14 + * precise terms see the accompanying LICENSE file.
1.15 + *
1.16 + * This software is provided "AS IS" with no warranty of any kind,
1.17 + * express or implied, and with no claim as to its suitability for any
1.18 + * purpose.
1.19 + *
1.20 + */
1.21 +
1.22 +#ifndef LEMON_BITS_SOLVER_BITS_H
1.23 +#define LEMON_BITS_SOLVER_BITS_H
1.24 +
1.25 +#include <vector>
1.26 +
1.27 +namespace lemon {
1.28 +
1.29 + namespace _solver_bits {
1.30 +
1.31 + class VarIndex {
1.32 + private:
1.33 + struct ItemT {
1.34 + int prev, next;
1.35 + int index;
1.36 + };
1.37 + std::vector<ItemT> items;
1.38 + int first_item, last_item, first_free_item;
1.39 +
1.40 + std::vector<int> cross;
1.41 +
1.42 + public:
1.43 +
1.44 + VarIndex()
1.45 + : first_item(-1), last_item(-1), first_free_item(-1) {
1.46 + }
1.47 +
1.48 + void clear() {
1.49 + first_item = -1;
1.50 + first_free_item = -1;
1.51 + items.clear();
1.52 + cross.clear();
1.53 + }
1.54 +
1.55 + int addIndex(int idx) {
1.56 + int n;
1.57 + if (first_free_item == -1) {
1.58 + n = items.size();
1.59 + items.push_back(ItemT());
1.60 + } else {
1.61 + n = first_free_item;
1.62 + first_free_item = items[n].next;
1.63 + if (first_free_item != -1) {
1.64 + items[first_free_item].prev = -1;
1.65 + }
1.66 + }
1.67 + items[n].index = idx;
1.68 + if (static_cast<int>(cross.size()) <= idx) {
1.69 + cross.resize(idx + 1, -1);
1.70 + }
1.71 + cross[idx] = n;
1.72 +
1.73 + items[n].prev = last_item;
1.74 + items[n].next = -1;
1.75 + if (last_item != -1) {
1.76 + items[last_item].next = n;
1.77 + } else {
1.78 + first_item = n;
1.79 + }
1.80 + last_item = n;
1.81 +
1.82 + return n;
1.83 + }
1.84 +
1.85 + int addIndex(int idx, int n) {
1.86 + while (n >= static_cast<int>(items.size())) {
1.87 + items.push_back(ItemT());
1.88 + items.back().prev = -1;
1.89 + items.back().next = first_free_item;
1.90 + if (first_free_item != -1) {
1.91 + items[first_free_item].prev = items.size() - 1;
1.92 + }
1.93 + first_free_item = items.size() - 1;
1.94 + }
1.95 + if (items[n].next != -1) {
1.96 + items[items[n].next].prev = items[n].prev;
1.97 + }
1.98 + if (items[n].prev != -1) {
1.99 + items[items[n].prev].next = items[n].next;
1.100 + } else {
1.101 + first_free_item = items[n].next;
1.102 + }
1.103 +
1.104 + items[n].index = idx;
1.105 + if (static_cast<int>(cross.size()) <= idx) {
1.106 + cross.resize(idx + 1, -1);
1.107 + }
1.108 + cross[idx] = n;
1.109 +
1.110 + items[n].prev = last_item;
1.111 + items[n].next = -1;
1.112 + if (last_item != -1) {
1.113 + items[last_item].next = n;
1.114 + } else {
1.115 + first_item = n;
1.116 + }
1.117 + last_item = n;
1.118 +
1.119 + return n;
1.120 + }
1.121 +
1.122 + void eraseIndex(int idx) {
1.123 + int n = cross[idx];
1.124 +
1.125 + if (items[n].prev != -1) {
1.126 + items[items[n].prev].next = items[n].next;
1.127 + } else {
1.128 + first_item = items[n].next;
1.129 + }
1.130 + if (items[n].next != -1) {
1.131 + items[items[n].next].prev = items[n].prev;
1.132 + } else {
1.133 + last_item = items[n].prev;
1.134 + }
1.135 +
1.136 + if (first_free_item != -1) {
1.137 + items[first_free_item].prev = n;
1.138 + }
1.139 + items[n].next = first_free_item;
1.140 + items[n].prev = -1;
1.141 + first_free_item = n;
1.142 +
1.143 + while (!cross.empty() && cross.back() == -1) {
1.144 + cross.pop_back();
1.145 + }
1.146 + }
1.147 +
1.148 + int maxIndex() const {
1.149 + return cross.size() - 1;
1.150 + }
1.151 +
1.152 + void shiftIndices(int idx) {
1.153 + for (int i = idx + 1; i < static_cast<int>(cross.size()); ++i) {
1.154 + cross[i - 1] = cross[i];
1.155 + if (cross[i] != -1) {
1.156 + --items[cross[i]].index;
1.157 + }
1.158 + }
1.159 + cross.back() = -1;
1.160 + cross.pop_back();
1.161 + while (!cross.empty() && cross.back() == -1) {
1.162 + cross.pop_back();
1.163 + }
1.164 + }
1.165 +
1.166 + void relocateIndex(int idx, int jdx) {
1.167 + cross[idx] = cross[jdx];
1.168 + items[cross[jdx]].index = idx;
1.169 + cross[jdx] = -1;
1.170 +
1.171 + while (!cross.empty() && cross.back() == -1) {
1.172 + cross.pop_back();
1.173 + }
1.174 + }
1.175 +
1.176 + int operator[](int idx) const {
1.177 + return cross[idx];
1.178 + }
1.179 +
1.180 + int operator()(int fdx) const {
1.181 + return items[fdx].index;
1.182 + }
1.183 +
1.184 + void firstItem(int& fdx) const {
1.185 + fdx = first_item;
1.186 + }
1.187 +
1.188 + void nextItem(int& fdx) const {
1.189 + fdx = items[fdx].next;
1.190 + }
1.191 +
1.192 + };
1.193 + }
1.194 +}
1.195 +
1.196 +#endif