/*
* Copyright 2015, 2016 Tagir Valeev
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package one.util.streamex;
import java.util.AbstractMap;
import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.Spliterator;
import one.util.streamex.IntStreamEx;
import one.util.streamex.PairPermutationSpliterator;
import org.junit.Test;
import static one.util.streamex.TestHelpers.*;
import static org.junit.Assert.*;
/**
* @author Tagir Valeev
*/
public class PairPermutationSpliteratorTest {
@Test
public void testSqrt() {
for (int rev = 0; rev < 1000; rev++) {
int row = (int) (Math.sqrt(8 * rev + 1) - 1) / 2;
int row2 = PairPermutationSpliterator.isqrt(rev);
assertEquals(row, row2);
}
for (int row : new int[] { 1_000_000_000, 2_000_000_000, Integer.MAX_VALUE - 1, Integer.MAX_VALUE }) {
assertEquals(row, PairPermutationSpliterator.isqrt(row * (row + 1L) / 2));
assertEquals(row - 1, PairPermutationSpliterator.isqrt(row * (row + 1L) / 2 - 1));
}
}
@Test
public void testCharacteristics() {
PairPermutationSpliterator<Integer, Integer> spltr = new PairPermutationSpliterator<>(Arrays.asList(1, 2, 3),
Integer::sum);
assertTrue(spltr.hasCharacteristics(Spliterator.ORDERED));
assertTrue(spltr.hasCharacteristics(Spliterator.SIZED));
assertTrue(spltr.hasCharacteristics(Spliterator.SUBSIZED));
assertEquals(3, spltr.getExactSizeIfKnown());
}
@Test
public void testSpliterator() {
for (int i : IntStreamEx.rangeClosed(2, 13).boxed()) {
List<Integer> input = IntStreamEx.range(i).boxed().toList();
List<Map.Entry<Integer, Integer>> expected = IntStreamEx.range(i)
.<Map.Entry<Integer, Integer>> flatMapToObj(
a -> IntStreamEx.range(a + 1, i).mapToObj(b -> new AbstractMap.SimpleEntry<>(a, b))).toList();
checkSpliterator("#" + i, expected, () -> new PairPermutationSpliterator<>(input,
AbstractMap.SimpleEntry<Integer, Integer>::new));
}
}
}