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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2025, 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. *
* *
* As an exception, when this program is distributed through (i) the *
* App Store by Apple Inc.; (ii) the Mac App Store by Apple Inc.; or *
* (iii) Google Play by Google Inc., then that store may impose any *
* digital rights management, device limits and/or redistribution *
* restrictions that are required by its terms of service. *
* *
* 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, see <https://www.gnu.org/licenses/>. *
* *
**************************************************************************/
#include <mutex>
#include <sstream>
#include "maths/perm.h"
namespace regina {
Perm<6>::Code2 (*Perm<6>::products_)[720] = nullptr;
namespace {
std::mutex precomputeMutex;
}
void Perm<6>::precompute() {
std::lock_guard<std::mutex> lock(precomputeMutex);
if (! products_) {
products_ = new Code2[720][720];
for (Code2 i = 0; i < 720; ++i)
for (Code2 j = 0; j < 720; ++j)
products_[i][j] = (Perm<6>(i) * Perm<6>(j)).code2_;
}
}
std::string Perm<6>::str() const {
char ans[7];
for (int i = 0; i < 6; i++)
ans[i] = static_cast<char>('0' + (*this)[i]);
ans[6] = 0;
return ans;
}
std::string Perm<6>::trunc(int len) const {
char ans[7];
for (int i = 0; i < len; ++i)
ans[i] = static_cast<char>('0' + (*this)[i]);
ans[len] = 0;
return ans;
}
} // namespace regina
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