Current File : //proc/309157/root/home/waritko/yacy/source/net/yacy/cora/sorting/Array.java
/**
* Array
* Copyright 2011 by Michael Peter Christen, mc@yacy.net, Frankfurt a. M., Germany
* First released 16.07.2011 at http://yacy.net
*
* $LastChangedDate: 2011-05-30 10:53:58 +0200 (Mo, 30 Mai 2011) $
* $LastChangedRevision: 7759 $
* $LastChangedBy: orbiter $
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program in the file lgpl21.txt
* If not, see <http://www.gnu.org/licenses/>.
*/
package net.yacy.cora.sorting;
import java.util.ArrayList;
import java.util.Random;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.LinkedBlockingQueue;
/**
* an abstraction of the quicksort from the java.util.Array class
* @author admin
*
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public class Array {
public static <A> void sort(final Sortable<A> x) {
sort(x, 0, x.size(), x.buffer(), 0);
}
private static <A> void sort(final Sortable<A> x, final int o, final int l, final A f, final int depth) {
// in case of small arrays we do not need a quicksort
if (l < 7) {
for (int i = o; i < l + o; i++) {
for (int j = i; j > o && x.compare(x.get(j, false), x.get(j - 1, false)) < 0; j--) x.swap(j, j - 1, f);
}
return;
}
// find the pivot element
int m = o + (l >> 1);
if (l > 7) {
int k = o;
int n = o + l - 1;
if (l > 40) {
final int s = l / 8;
k = med3(x, k , k + s, k + 2 * s);
m = med3(x, m - s , m , m + s );
n = med3(x, n - 2 * s, n - s, n );
}
m = med3(x, k, m, n);
}
final A p = x.get(m, true);
// do a partitioning of the sequence
int a = o, b = a, c = o + l - 1, d = c;
A _v;
while (true) {
while (c >= b && x.compare(p, (_v = x.get(b, false))) >= 0) {
if (x.compare(_v, p) == 0) x.swap(a++, b, f);
b++;
}
while (c >= b && x.compare((_v = x.get(c, false)), p) >= 0) {
if (x.compare(_v, p) == 0) x.swap(c, d--, f);
c--;
}
if (b > c) break;
x.swap(b++, c--, f);
}
// swap all
int s;
final int n = o + l;
s = Math.min(a - o, b - a );
swap(x, o, b - s, s, f);
s = Math.min(d - c, n - d - 1);
swap(x, b, n - s, s, f);
// recursively sort partitions
final int s0 = b - a;
if (s0 > 1) {
sort(x, o, s0, f, depth + 1);
}
final int s1 = d - c;
if (s1 > 1) {
sort(x, n - s1, s1, x.buffer(), depth + 1);
}
}
private static <A> void swap(final Sortable<A> x, int a, int b, final int n, final A buffer) {
if (n == 1) {
x.swap(a, b, buffer);
} else {
for (int i = 0; i < n; i++, a++, b++) x.swap(a, b, buffer);
}
}
private static <A> int med3(final Sortable<A> x, final int a, final int b, final int c) {
final A _a = x.get(a, false);
final A _b = x.get(b, false);
final A _c = x.get(c, false);
return (x.compare(_a, _b) < 0 ?
(x.compare(_b, _c) < 0 ? b : x.compare(_a, _c) < 0 ? c : a) :
(x.compare(_c, _b) < 0 ? b : x.compare(_c, _a) < 0 ? c : a));
}
private static class P extends ArrayList<Integer> implements Sortable<Integer> {
private static final long serialVersionUID = 1L;
public P() {
super();
}
@Override
public int compare(final Integer o1, final Integer o2) {
return o1.compareTo(o2);
}
@Override
public Integer buffer() {
return new Integer(0);
}
@Override
public void swap(final int i, final int j, Integer buffer) {
buffer = get(i);
set(i, get(j));
set(j, buffer);
}
@Override
public void delete(final int i) {
this.remove(i);
}
@Override
public Integer get(final int i, final boolean clone) {
return get(i);
}
}
public static <A> void uniq(final Sortable<A> x) {
if (x.size() < 2) return;
int i = x.size() - 1;
A a = x.get(i--, true), b;
while (i >= 0) {
b = x.get(i, true);
if (x.compare(a, b) == 0) {
x.delete(i);
} else {
a = b;
}
i--;
}
}
public static void main(final String[] args) {
final int count = 1000000;
final P test = new P();
Random r = new Random(0);
for (int i = 0; i < count; i++) {
test.add(r.nextInt());
}
r = new Random(0);
for (int i = 0; i < count; i++) {
test.add(r.nextInt());
}
final long t0 = System.currentTimeMillis();
sort(test);
final long t1 = System.currentTimeMillis();
System.out.println("sort = " + (t1 - t0) + "ms");
//uniq(test);
final long t2 = System.currentTimeMillis();
System.out.println("uniq = " + (t2 - t1) + "ms");
System.out.println("result: " + test.size());
}
}
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