Jip J. Dekker
981be2067e
git-subtree-dir: software/gecode_on_replay git-subtree-split: 8051d92b9c89e49cccfbd1c201371580d7703ab4
381 lines
12 KiB
C++
381 lines
12 KiB
C++
/* -*- mode: C++; c-basic-offset: 2; indent-tabs-mode: nil -*- */
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/*
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* Main authors:
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* Guido Tack <tack@gecode.org>
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*
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* Copyright:
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* Guido Tack, 2006
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*
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* This file is part of Gecode, the generic constraint
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* development environment:
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* http://www.gecode.org
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be
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* included in all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*
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*/
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#include <gecode/gist/spacenode.hh>
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#include <gecode/gist/visualnode.hh>
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#include <gecode/gist/stopbrancher.hh>
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#include <gecode/search.hh>
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#include <stack>
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#include <QString>
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#include <QVector>
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namespace Gecode { namespace Gist {
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/// \brief Representation of a branch in the search tree
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class Branch {
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public:
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/// Alternative number
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int alternative;
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/// The best space known when the branch was created
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SpaceNode* ownBest;
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const Choice* choice;
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/// Constructor
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Branch(int a, const Choice* c, SpaceNode* best = nullptr)
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: alternative(a), ownBest(best) {
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choice = c;
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}
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};
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BestNode::BestNode(SpaceNode* s0) : s(s0) {}
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int
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SpaceNode::recompute(NodeAllocator& na,
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BestNode* curBest, int c_d, int a_d) {
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int rdist = 0;
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if (copy == nullptr) {
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SpaceNode* curNode = this;
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SpaceNode* lastFixpoint = nullptr;
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lastFixpoint = curNode;
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std::stack<Branch> stck;
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int idx = getIndex(na);
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while (curNode->copy == nullptr) {
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SpaceNode* parent = curNode->getParent(na);
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int parentIdx = curNode->getParent();
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int alternative = curNode->getAlternative(na);
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SpaceNode* ownBest = na.best(idx);
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Branch b(alternative, parent->choice,
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curBest == nullptr ? nullptr : ownBest);
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stck.push(b);
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curNode = parent;
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idx = parentIdx;
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rdist++;
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}
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Space* curSpace;
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if (Support::marked(curNode->copy)) {
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curSpace = static_cast<Space*>(Support::unmark(curNode->copy));
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curNode->copy = nullptr;
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a_d = -1;
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} else {
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curSpace = curNode->copy->clone();
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curNode->setDistance(0);
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}
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SpaceNode* lastBest = nullptr;
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SpaceNode* middleNode = curNode;
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int curDist = 0;
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while (!stck.empty()) {
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if (a_d >= 0 &&
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curDist > a_d &&
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curDist == rdist / 2) {
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if (curSpace->status() == SS_FAILED) {
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copy = static_cast<Space*>(Support::mark(curSpace));
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return rdist;
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} else {
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middleNode->copy = curSpace->clone();
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}
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}
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Branch b = stck.top(); stck.pop();
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if(middleNode == lastFixpoint) {
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curSpace->status();
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}
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curSpace->commit(*b.choice, b.alternative);
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if (b.ownBest != nullptr && b.ownBest != lastBest) {
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b.ownBest->acquireSpace(na,curBest, c_d, a_d);
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Space* ownBestSpace =
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static_cast<Space*>(Support::funmark(b.ownBest->copy));
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if (ownBestSpace->status() != SS_SOLVED) {
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// in the presence of weakly monotonic propagators, we may have to
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// use search to find the solution here
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ownBestSpace = Gecode::dfs(ownBestSpace);
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if (Support::marked(b.ownBest->copy)) {
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delete static_cast<Space*>(Support::unmark(b.ownBest->copy));
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b.ownBest->copy =
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static_cast<Space*>(Support::mark(ownBestSpace));
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} else {
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delete b.ownBest->copy;
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b.ownBest->copy = ownBestSpace;
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}
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}
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curSpace->constrain(*ownBestSpace);
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lastBest = b.ownBest;
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}
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curDist++;
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middleNode = middleNode->getChild(na,b.alternative);
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middleNode->setDistance(curDist);
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}
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copy = static_cast<Space*>(Support::mark(curSpace));
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}
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return rdist;
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}
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void
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SpaceNode::acquireSpace(NodeAllocator& na,
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BestNode* curBest, int c_d, int a_d) {
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SpaceNode* p = getParent(na);
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int parentIdx = getParent();
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int idx = getIndex(na);
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if (getStatus() == UNDETERMINED && curBest != nullptr &&
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na.best(idx) == nullptr &&
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p != nullptr && curBest->s != na.best(parentIdx)) {
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na.setBest(idx, curBest->s->getIndex(na));
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}
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SpaceNode* ownBest = na.best(idx);
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if (copy == nullptr && p != nullptr && p->copy != nullptr &&
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Support::marked(p->copy)) {
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// If parent has a working space, steal it
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copy = p->copy;
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p->copy = nullptr;
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if (p->choice != nullptr)
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static_cast<Space*>(Support::unmark(copy))->
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commit(*p->choice, getAlternative(na));
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if (ownBest != nullptr) {
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ownBest->acquireSpace(na,curBest, c_d, a_d);
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Space* ownBestSpace =
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static_cast<Space*>(Support::funmark(ownBest->copy));
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if (ownBestSpace->status() != SS_SOLVED) {
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// in the presence of weakly monotonic propagators, we may have to
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// use search to find the solution here
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ownBestSpace = Gecode::dfs(ownBestSpace);
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if (Support::marked(ownBest->copy)) {
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delete static_cast<Space*>(Support::unmark(ownBest->copy));
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ownBest->copy =
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static_cast<Space*>(Support::mark(ownBestSpace));
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} else {
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delete ownBest->copy;
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ownBest->copy = ownBestSpace;
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}
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}
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static_cast<Space*>(Support::unmark(copy))->constrain(*ownBestSpace);
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}
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int d = p->getDistance()+1;
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if (d > c_d && c_d >= 0 &&
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static_cast<Space*>(Support::unmark(copy))->status() == SS_BRANCH) {
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copy = static_cast<Space*>(Support::unmark(copy));
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d = 0;
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}
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setDistance(d);
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}
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if (copy == nullptr) {
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if (recompute(na, curBest, c_d, a_d) > c_d && c_d >= 0 &&
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static_cast<Space*>(Support::unmark(copy))->status() == SS_BRANCH) {
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copy = static_cast<Space*>(Support::unmark(copy));
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setDistance(0);
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}
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}
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// always return a fixpoint
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static_cast<Space*>(Support::funmark(copy))->status();
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if (Support::marked(copy) && p != nullptr && isOpen() &&
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p->copy != nullptr && p->getNoOfOpenChildren(na) == 1 &&
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!p->isRoot()) {
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// last alternative optimization
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copy = static_cast<Space*>(Support::unmark(copy));
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delete static_cast<Space*>(Support::funmark(p->copy));
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p->copy = nullptr;
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setDistance(0);
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p->setDistance(p->getParent(na)->getDistance()+1);
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}
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}
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void
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SpaceNode::closeChild(const NodeAllocator& na,
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bool hadFailures, bool hadSolutions) {
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setHasFailedChildren(hasFailedChildren() || hadFailures);
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setHasSolvedChildren(hasSolvedChildren() || hadSolutions);
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bool allClosed = true;
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for (int i=getNumberOfChildren(); i--;) {
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if (getChild(na,i)->isOpen()) {
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allClosed = false;
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break;
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}
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}
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if (allClosed) {
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setHasOpenChildren(false);
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for (unsigned int i=0; i<getNumberOfChildren(); i++)
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setHasSolvedChildren(hasSolvedChildren() ||
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getChild(na,i)->hasSolvedChildren());
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SpaceNode* p = getParent(na);
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if (p != nullptr) {
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delete static_cast<Space*>(Support::funmark(copy));
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copy = nullptr;
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p->closeChild(na, hasFailedChildren(), hasSolvedChildren());
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}
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} else {
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if (hadSolutions) {
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setHasSolvedChildren(true);
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SpaceNode* p = getParent(na);
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while (p != nullptr && !p->hasSolvedChildren()) {
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p->setHasSolvedChildren(true);
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p = p->getParent(na);
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}
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}
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if (hadFailures) {
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SpaceNode* p = getParent(na);
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while (p != nullptr && !p->hasFailedChildren()) {
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p->setHasFailedChildren(true);
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p = p->getParent(na);
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}
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}
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}
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}
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SpaceNode::SpaceNode(Space* root)
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: Node(-1, root==nullptr),
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copy(root), choice(nullptr), nstatus(0) {
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if (root == nullptr) {
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setStatus(FAILED);
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setHasSolvedChildren(false);
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setHasFailedChildren(true);
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} else {
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setStatus(UNDETERMINED);
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setHasSolvedChildren(false);
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setHasFailedChildren(false);
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}
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}
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void
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SpaceNode::dispose(void) {
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delete choice;
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delete static_cast<Space*>(Support::funmark(copy));
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}
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int
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SpaceNode::getNumberOfChildNodes(NodeAllocator& na,
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BestNode* curBest, Statistics& stats,
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int c_d, int a_d) {
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int kids = 0;
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if (isUndetermined()) {
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stats.undetermined--;
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acquireSpace(na, curBest, c_d, a_d);
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QVector<QString> labels;
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switch (static_cast<Space*>(Support::funmark(copy))->status(stats)) {
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case SS_FAILED:
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{
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purge(na);
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kids = 0;
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setHasOpenChildren(false);
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setHasSolvedChildren(false);
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setHasFailedChildren(true);
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setStatus(FAILED);
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stats.failures++;
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SpaceNode* p = getParent(na);
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if (p != nullptr)
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p->closeChild(na, true, false);
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}
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break;
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case SS_SOLVED:
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{
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// Deletes all pending branchers
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(void) static_cast<Space*>(Support::funmark(copy))->choice();
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kids = 0;
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setStatus(SOLVED);
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setHasOpenChildren(false);
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setHasSolvedChildren(true);
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setHasFailedChildren(false);
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stats.solutions++;
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if (curBest != nullptr) {
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curBest->s = this;
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}
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SpaceNode* p = getParent(na);
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if (p != nullptr)
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p->closeChild(na, false, true);
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}
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break;
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case SS_BRANCH:
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{
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Space* s = static_cast<Space*>(Support::funmark(copy));
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choice = s->choice();
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kids = choice->alternatives();
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setHasOpenChildren(true);
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if (dynamic_cast<const StopChoice*>(choice)) {
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setStatus(STOP);
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} else {
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setStatus(BRANCH);
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stats.choices++;
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}
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stats.undetermined += kids;
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for (int i=0; i<kids; i++) {
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std::ostringstream oss;
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s->print(*choice,i,oss);
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labels.push_back(QString(oss.str().c_str()));
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}
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}
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break;
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}
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static_cast<VisualNode*>(this)->changedStatus(na);
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setNumberOfChildren(kids, na);
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} else {
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kids = getNumberOfChildren();
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}
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return kids;
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}
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int
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SpaceNode::getNoOfOpenChildren(const NodeAllocator& na) {
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if (!hasOpenChildren())
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return 0;
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int noOfOpenChildren = 0;
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for (int i=getNumberOfChildren(); i--;)
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noOfOpenChildren += (getChild(na,i)->isOpen());
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return noOfOpenChildren;
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}
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}}
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// STATISTICS: gist-any
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