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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2009, Ben Burton *
* For further details contact Ben Burton (bab@debian.org). *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 2 of the *
* License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public *
* License along with this program; if not, write to the Free *
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, *
* MA 02110-1301, USA. *
* *
**************************************************************************/
/* end stub */
#include <algorithm>
#include "split/nsigisomorphism.h"
namespace regina {
NSigPartialIsomorphism::NSigPartialIsomorphism(
const NSigPartialIsomorphism& iso) : nLabels(iso.nLabels),
nCycles(iso.nCycles),
labelImage(iso.nLabels ? new unsigned[iso.nLabels] : 0),
cyclePreImage(iso.nCycles ? new unsigned[iso.nCycles] : 0),
cycleStart(iso.nCycles ? new unsigned[iso.nCycles] : 0), dir(iso.dir) {
if (iso.nLabels)
std::copy(iso.labelImage, iso.labelImage + iso.nLabels, labelImage);
if (iso.nCycles) {
std::copy(iso.cyclePreImage, iso.cyclePreImage + iso.nCycles,
cyclePreImage);
std::copy(iso.cycleStart, iso.cycleStart + iso.nCycles, cycleStart);
}
}
NSigPartialIsomorphism::NSigPartialIsomorphism(
const NSigPartialIsomorphism& base,
unsigned newLabels, unsigned newCycles) : nLabels(newLabels),
nCycles(newCycles),
labelImage(newLabels ? new unsigned[newLabels] : 0),
cyclePreImage(newCycles ? new unsigned[newCycles] : 0),
cycleStart(newCycles ? new unsigned[newCycles] : 0), dir(base.dir) {
if (base.nLabels)
std::copy(base.labelImage, base.labelImage + base.nLabels, labelImage);
if (base.nCycles) {
std::copy(base.cyclePreImage, base.cyclePreImage + base.nCycles,
cyclePreImage);
std::copy(base.cycleStart, base.cycleStart + base.nCycles, cycleStart);
}
}
void NSigPartialIsomorphism::makeCanonical(const NSignature& sig,
unsigned fromCycleGroup) {
unsigned fromCycle, toCycle;
unsigned c, i;
unsigned cycleLen;
unsigned start1, start2;
// Deal with each cycle group separately.
for ( ; sig.cycleGroupStart[fromCycleGroup] < nCycles; fromCycleGroup++) {
fromCycle = sig.cycleGroupStart[fromCycleGroup];
toCycle = sig.cycleGroupStart[fromCycleGroup + 1];
if (toCycle > nCycles)
toCycle = nCycles;
if (fromCycle >= toCycle)
continue;
// Determine where each cycle should start.
cycleLen = sig.cycleStart[fromCycle + 1] - sig.cycleStart[fromCycle];
for (c = fromCycle; c < toCycle; c++) {
start1 = start2 = cycleLen;
for (i = 0; i < cycleLen; i++)
if (start1 == cycleLen ||
labelImage[sig.label[sig.cycleStart[c] + i]] <
labelImage[sig.label[sig.cycleStart[c] + start1]]) {
start1 = i;
start2 = cycleLen;
} else if (labelImage[sig.label[sig.cycleStart[c] + i]] ==
labelImage[sig.label[sig.cycleStart[c] + start1]])
start2 = i;
if (start2 == cycleLen)
cycleStart[c] = start1;
else {
// Two possible starting points; we must choose between them.
if (NSignature::cycleCmp(sig, c, start1, dir, labelImage,
sig, c, start2, dir, labelImage) <= 0)
cycleStart[c] = start1;
else
cycleStart[c] = start2;
}
}
// At this point we now know where each cycle starts under the new
// labelling. It's now time to determine in which order the cycles
// should be presented.
for (c = fromCycle; c < toCycle; c++)
cyclePreImage[c] = c;
std::sort(cyclePreImage + fromCycle, cyclePreImage + toCycle,
ShorterCycle(sig, *this));
}
}
int NSigPartialIsomorphism::compareWith(const NSignature& sig,
const NSigPartialIsomorphism* other, unsigned fromCycleGroup) const {
int result;
for (unsigned c = sig.cycleGroupStart[fromCycleGroup]; c < nCycles; c++) {
if (other)
result = NSignature::cycleCmp(sig, cyclePreImage[c],
cycleStart[cyclePreImage[c]], dir, labelImage,
sig, other->cyclePreImage[c],
other->cycleStart[other->cyclePreImage[c]], other->dir,
other->labelImage);
else
result = NSignature::cycleCmp(sig, cyclePreImage[c],
cycleStart[cyclePreImage[c]], dir, labelImage,
sig, c, 0, 1, 0);
if (result < 0)
return -1;
if (result > 0)
return 1;
}
return 0;
}
} // namespace regina
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