package de.lmu.ifi.dbs.elki.utilities.datastructures.heap;

/*
 This file is part of ELKI:
 Environment for Developing KDD-Applications Supported by Index-Structures

 Copyright (C) 2015
 Ludwig-Maximilians-Universität München
 Lehr- und Forschungseinheit für Datenbanksysteme
 ELKI Development Team

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Affero General Public License for more details.

 You should have received a copy of the GNU Affero General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

import static org.junit.Assert.assertTrue;

import java.util.Random;

import org.junit.Test;

import de.lmu.ifi.dbs.elki.JUnit4Test;

/**
 * Perform standard unit tests on the double-indexed heap structures.
 * 
 * @author Erich Schubert
 */
public class TestDoubleHeap implements JUnit4Test {
  @Test
  public void testDoubleMinHeap() {
    Random r = new Random();
    DoubleMinHeap heap = new DoubleMinHeap();
    for (int i = 0; i < 1000; i++) {
      double key = r.nextDouble();
      heap.add(key);
    }
    double cur = Double.NEGATIVE_INFINITY;
    for (int i = 0; i < 500; i++) {
      assertTrue("Heap incorrectly ordered!", cur <= heap.peek());
      cur = heap.peek();
      heap.poll();
    }
    for (int i = 0; i < 10000; i++) {
      double key = r.nextDouble();
      heap.add(key);
    }
    cur = Double.NEGATIVE_INFINITY;
    while (heap.size() > 0) {
      assertTrue("Heap incorrectly ordered!", cur <= heap.peek());
      cur = heap.peek();
      heap.poll();
    }
  }

  @Test
  public void testDoubleMaxHeap() {
    Random r = new Random();
    DoubleMaxHeap heap = new DoubleMaxHeap();
    for (int i = 0; i < 1000; i++) {
      double key = r.nextDouble();
      heap.add(key);
    }
    double cur = Double.POSITIVE_INFINITY;
    for (int i = 0; i < 500; i++) {
      assertTrue("Heap incorrectly ordered! "+cur+" < "+heap.peek(), cur >= heap.peek());
      cur = heap.peek();
      heap.poll();
    }
    for (int i = 0; i < 10000; i++) {
      double key = r.nextDouble();
      heap.add(key);
    }
    cur = Double.POSITIVE_INFINITY;
    while (heap.size() > 0) {
      assertTrue("Heap incorrectly ordered!", cur >= heap.peek());
      cur = heap.peek();
      heap.poll();
    }
  }
}