diff options
| -rw-r--r-- | src/common/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | src/common/apply_permutation.h | 61 | ||||
| -rw-r--r-- | tests/unit_tests/CMakeLists.txt | 1 | ||||
| -rw-r--r-- | tests/unit_tests/apply_permutation.cpp | 45 |
4 files changed, 108 insertions, 0 deletions
diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt index 55b8ad3e6..5adc9caf0 100644 --- a/src/common/CMakeLists.txt +++ b/src/common/CMakeLists.txt @@ -48,6 +48,7 @@ endif() set(common_headers) set(common_private_headers + apply_permutation.h base58.h boost_serialization_helper.h command_line.h diff --git a/src/common/apply_permutation.h b/src/common/apply_permutation.h new file mode 100644 index 000000000..4de224690 --- /dev/null +++ b/src/common/apply_permutation.h @@ -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]); }); +} + +} diff --git a/tests/unit_tests/CMakeLists.txt b/tests/unit_tests/CMakeLists.txt index 2f62dc2aa..4286e0374 100644 --- a/tests/unit_tests/CMakeLists.txt +++ b/tests/unit_tests/CMakeLists.txt @@ -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 diff --git a/tests/unit_tests/apply_permutation.cpp b/tests/unit_tests/apply_permutation.cpp new file mode 100644 index 000000000..888a00746 --- /dev/null +++ b/tests/unit_tests/apply_permutation.cpp @@ -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})); +} |