/**

* Copyright 2020-2023 by XGBoost Contributors

*/

#include <gtest/gtest.h>

#include <xgboost/context.h> // Context

#include <xgboost/span.h>

#include <algorithm> // is_sorted

#include "../../../src/common/algorithm.h"

namespace xgboost {

namespace common {

TEST(Algorithm, ArgSort) {

Context ctx;

std::vector<float> inputs{3.0, 2.0, 1.0};

auto ret = ArgSort<bst_feature_t>(&ctx, inputs.cbegin(), inputs.cend());

std::vector<bst_feature_t> sol{2, 1, 0};

ASSERT_EQ(ret, sol);

}

TEST(Algorithm, Sort) {

Context ctx;

ctx.Init(Args{{"nthread", "8"}});

std::vector<float> inputs{3.0, 1.0, 2.0};

Sort(&ctx, inputs.begin(), inputs.end(), std::less<>{});

ASSERT_TRUE(std::is_sorted(inputs.cbegin(), inputs.cend()));

inputs = {3.0, 1.0, 2.0};

StableSort(&ctx, inputs.begin(), inputs.end(), std::less<>{});

ASSERT_TRUE(std::is_sorted(inputs.cbegin(), inputs.cend()));

}

} // namespace common

} // namespace xgboost