common: add apply_permutation file and function

This algorithm is adapted from Raymond Chen's code:
https://blogs.msdn.microsoft.com/oldnewthing/20170109-00/?p=95145
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moneromooo-monero 2017-09-13 09:22:16 +01:00
parent 02e5dcd2fa
commit 0c36b9f931
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@ -48,6 +48,7 @@ endif()
set(common_headers)
set(common_private_headers
apply_permutation.h
base58.h
boost_serialization_helper.h
command_line.h

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@ -0,0 +1,61 @@
// Copyright (c) 2017, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Most of this file is originally copyright (c) 2017 Raymond Chen, Microsoft
// This algorithm is adapted from Raymond Chen's code:
// https://blogs.msdn.microsoft.com/oldnewthing/20170109-00/?p=95145
#include <vector>
#include <functional>
namespace tools
{
void apply_permutation(std::vector<size_t> permutation, const std::function<void(size_t, size_t)> &swap)
{
for (size_t i = 0; i < permutation.size(); ++i)
{
size_t current = i;
while (i != permutation[current])
{
size_t next = permutation[current];
swap(current, next);
permutation[current] = current;
current = next;
}
permutation[current] = current;
}
}
template<typename T>
void apply_permutation(const std::vector<size_t> &permutation, std::vector<T> &v)
{
apply_permutation(permutation, [&v](size_t i0, size_t i1){ std::swap(v[i0], v[i1]); });
}
}

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@ -27,6 +27,7 @@
# THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
set(unit_tests_sources
apply_permutation.cpp
address_from_url.cpp
ban.cpp
base58.cpp

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@ -0,0 +1,45 @@
// Copyright (c) 2017, The Monero Project
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without modification, are
// permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this list of
// conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice, this list
// of conditions and the following disclaimer in the documentation and/or other
// materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors may be
// used to endorse or promote products derived from this software without specific
// prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "gtest/gtest.h"
#include "common/apply_permutation.h"
TEST(apply_permutation, empty)
{
std::vector<int> v = {};
tools::apply_permutation({}, v);
ASSERT_EQ(v, std::vector<int>({}));
}
TEST(apply_permutation, reorder)
{
// 0 1 2 3 4 5 6
std::vector<int> v = {8, 4, 6, 1, 7, 2, 4};
tools::apply_permutation({3, 5, 6, 1, 2, 4, 0}, v);
ASSERT_EQ(v, std::vector<int>({1, 2, 4, 4, 6, 7, 8}));
}