/*
* RapidMiner
*
* Copyright (C) 2001-2008 by Rapid-I and the contributors
*
* Complete list of developers available at our web site:
*
* http://rapid-i.com
*
* 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/.
*/
package com.rapidminer.operator.learner.functions.kernel.jmysvm.util;
/**
* Implements a MaxHeap on n doubles and ints
*
* @author Stefan Rueping
* @version $Id: MaxHeap.java,v 1.3 2008/05/09 19:23:24 ingomierswa Exp $
*/
public class MaxHeap extends Heap {
public MaxHeap(int n) {
the_size = 0;
init(n);
};
public final void add(double value, int index) {
if (last < the_size) {
heap[last] = value;
indizes[last] = index;
last++;
if (last == the_size) {
for (int j = last; j > 0; j--) {
heapify(j - 1, last + 1 - j);
};
};
} else if (value >= heap[0]) {
heap[0] = value;
indizes[0] = index;
heapify(0, last);
};
};
protected final void heapify(int start, int size) {
double[] my_heap = heap;
boolean running = true;
int pos = 1;
int left, right, largest;
double dummyf;
int dummyi;
start--; // other variables counted from 1
while (running) {
left = 2 * pos;
right = left + 1;
if ((left <= size) && (my_heap[left + start] < my_heap[start + pos])) {
largest = left;
} else {
largest = pos;
};
if ((right <= size) && (my_heap[start + right] < my_heap[start + largest])) {
largest = right;
};
if (largest == pos) {
running = false;
} else {
dummyf = my_heap[start + pos];
dummyi = indizes[start + pos];
my_heap[start + pos] = my_heap[start + largest];
indizes[start + pos] = indizes[start + largest];
my_heap[start + largest] = dummyf;
indizes[start + largest] = dummyi;
pos = largest;
};
};
};
};