80 lines
2.4 KiB
C++
80 lines
2.4 KiB
C++
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/* SPDX-License-Identifier: GPL-3.0-or-later
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* Copyright © 2023-2024 The TokTok team.
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*/
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#include "sort.h"
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#include <gtest/gtest.h>
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#include <limits>
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#include <random>
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#include "sort_test_util.hh"
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namespace {
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TEST(MergeSort, BehavesLikeStdSort)
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{
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std::mt19937 rng;
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// INT_MAX-1 so later we have room to add 1 larger element if needed.
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std::uniform_int_distribution<int> dist{
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std::numeric_limits<int>::min(), std::numeric_limits<int>::max() - 1};
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constexpr auto int_funcs = sort_funcs<int>();
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// Test with int arrays.
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for (uint32_t i = 1; i < 500; ++i) {
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std::vector<int> vec(i);
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std::generate(std::begin(vec), std::end(vec), [&]() { return dist(rng); });
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auto sorted = vec;
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std::sort(sorted.begin(), sorted.end(), std::less<int>());
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// If vec was accidentally sorted, add another larger element that almost definitely makes
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// it not sorted.
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if (vec == sorted) {
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int const largest = *std::prev(sorted.end()) + 1;
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sorted.push_back(largest);
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vec.insert(vec.begin(), largest);
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}
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ASSERT_NE(vec, sorted);
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// Just pass some arbitrary "self" to make sure the callbacks pass it through.
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ASSERT_TRUE(merge_sort(vec.data(), vec.size(), &i, &int_funcs));
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ASSERT_EQ(vec, sorted);
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}
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}
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TEST(MergeSort, WorksWithNonTrivialTypes)
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{
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std::mt19937 rng;
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std::uniform_int_distribution<int> dist{
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std::numeric_limits<int>::min(), std::numeric_limits<int>::max()};
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constexpr auto string_funcs = sort_funcs<std::string>();
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// Test with std::string arrays.
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for (uint32_t i = 1; i < 500; ++i) {
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std::vector<std::string> vec(i);
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std::generate(std::begin(vec), std::end(vec), [&]() { return std::to_string(dist(rng)); });
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auto sorted = vec;
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std::sort(sorted.begin(), sorted.end(), std::less<std::string>());
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// If vec was accidentally sorted, add another larger element that almost definitely makes
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// it not sorted.
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if (vec == sorted) {
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std::string const largest = "larger than largest int";
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sorted.push_back(largest);
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vec.insert(vec.begin(), largest);
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}
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ASSERT_NE(vec, sorted);
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// Just pass some arbitrary "self" to make sure the callbacks pass it through.
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ASSERT_TRUE(merge_sort(vec.data(), vec.size(), &i, &string_funcs));
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ASSERT_EQ(vec, sorted);
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}
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}
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} // namespace
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