solidity/tools/yulPhaser/PairSelections.cpp
2020-06-04 17:17:40 +02:00

107 lines
3.2 KiB
C++

/*
This file is part of solidity.
solidity 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 3 of the License, or
(at your option) any later version.
solidity 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 solidity. If not, see <http://www.gnu.org/licenses/>.
*/
#include <tools/yulPhaser/PairSelections.h>
#include <tools/yulPhaser/Selections.h>
#include <tools/yulPhaser/SimulationRNG.h>
#include <cmath>
using namespace std;
using namespace solidity::phaser;
vector<tuple<size_t, size_t>> RandomPairSelection::materialise(size_t _poolSize) const
{
if (_poolSize < 2)
return {};
auto count = static_cast<size_t>(round(_poolSize * m_selectionSize));
vector<tuple<size_t, size_t>> selection;
for (size_t i = 0; i < count; ++i)
{
size_t index1 = SimulationRNG::uniformInt(0, _poolSize - 1);
size_t index2;
do
{
index2 = SimulationRNG::uniformInt(0, _poolSize - 1);
} while (index1 == index2);
selection.emplace_back(index1, index2);
}
return selection;
}
vector<tuple<size_t, size_t>> PairsFromRandomSubset::materialise(size_t _poolSize) const
{
vector<size_t> selectedIndices = RandomSubset(m_selectionChance).materialise(_poolSize);
if (selectedIndices.size() % 2 != 0)
{
if (selectedIndices.size() < _poolSize && SimulationRNG::bernoulliTrial(0.5))
{
do
{
size_t extraIndex = SimulationRNG::uniformInt(0, selectedIndices.size() - 1);
if (find(selectedIndices.begin(), selectedIndices.end(), extraIndex) == selectedIndices.end())
selectedIndices.push_back(extraIndex);
} while (selectedIndices.size() % 2 != 0);
}
else
selectedIndices.erase(
selectedIndices.begin() +
static_cast<ptrdiff_t>(SimulationRNG::uniformInt(0, selectedIndices.size() - 1))
);
}
assert(selectedIndices.size() % 2 == 0);
vector<tuple<size_t, size_t>> selectedPairs;
for (size_t i = selectedIndices.size() / 2; i > 0; --i)
{
size_t position1 = SimulationRNG::uniformInt(0, selectedIndices.size() - 1);
size_t value1 = selectedIndices[position1];
selectedIndices.erase(selectedIndices.begin() + static_cast<ptrdiff_t>(position1));
size_t position2 = SimulationRNG::uniformInt(0, selectedIndices.size() - 1);
size_t value2 = selectedIndices[position2];
selectedIndices.erase(selectedIndices.begin() + static_cast<ptrdiff_t>(position2));
selectedPairs.emplace_back(value1, value2);
}
assert(selectedIndices.empty());
return selectedPairs;
}
vector<tuple<size_t, size_t>> PairMosaicSelection::materialise(size_t _poolSize) const
{
if (_poolSize < 2)
return {};
size_t count = static_cast<size_t>(round(_poolSize * m_selectionSize));
vector<tuple<size_t, size_t>> selection;
for (size_t i = 0; i < count; ++i)
{
tuple<size_t, size_t> pair = m_pattern[i % m_pattern.size()];
selection.emplace_back(min(get<0>(pair), _poolSize - 1), min(get<1>(pair), _poolSize - 1));
}
return selection;
}