/*
    * Licensed to the Hipparchus project under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The Hipparchus project licenses this file to You 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
    *
    *      https://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 org.hipparchus.util;
  
  import static org.junit.Assert.assertEquals;
  
  import java.util.Arrays;
  import java.util.Random;
  
  import org.junit.Test;
  
  public class KthSelectorTest {
  
      @Test
      public void testRandom() {
          
          final int numIterations = 100000;
          final double[] possibleValues = {Double.NaN, Double.NEGATIVE_INFINITY, Double.POSITIVE_INFINITY, Double.MAX_VALUE, Double.MIN_VALUE, -10, -9, -8, -7, -6, -5, -4, -3, -2, -1, -0., 0., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
          final Random rnd = new Random(0);
          for (int i = 0; i < numIterations; ++i) {
              
              final int dataSize = rnd.nextInt(30);
  
              final double[] data = new double[dataSize];
  
              for (int j = 0; j < dataSize; ++j) {
                  data[j] = possibleValues[rnd.nextInt(possibleValues.length)];
              }
              
              final double[] dataSorted = Arrays.copyOf(data, data.length);
              Arrays.sort(dataSorted);
  
              for (int j = 0; j < dataSize; ++j) {
  
                  final double[] dataTmp = Arrays.copyOf(data, data.length);
                  final double resultKthSelector = new KthSelector().select(dataTmp, null, j);
                  final double resultSort = dataSorted[j];
                  assertEquals(Double.doubleToLongBits(resultKthSelector), Double.doubleToLongBits(resultSort));
              }
          }
      }
  }