/**
* Shuffles the specified big array using the specified pseudorandom number generator.
*
* @param a the big array to be shuffled.
* @param random a pseudorandom number generator (please use a <a
* href="http://dsiutils.dsi.unimi.it/docs/it/unimi/dsi/util/XorShiftStarRandom.html">XorShift*</a>
* generator).
* @return <code>a</code>.
*/
public static boolean[][] shuffle(final boolean[][] a, final Random random) {
for (long i = length(a); i-- != 0; ) {
final long p = (random.nextLong() & 0x7FFFFFFFFFFFFFFFL) % (i + 1);
final boolean t = get(a, i);
set(a, i, get(a, p));
set(a, p, t);
}
return a;
}
/**
* Shuffles the specified big array fragment using the specified pseudorandom number generator.
*
* @param a the big array to be shuffled.
* @param from the index of the first element (inclusive) to be shuffled.
* @param to the index of the last element (exclusive) to be shuffled.
* @param random a pseudorandom number generator (please use a <a
* href="http://dsiutils.dsi.unimi.it/docs/it/unimi/dsi/util/XorShiftStarRandom.html">XorShift*</a>
* generator).
* @return <code>a</code>.
*/
public static boolean[][] shuffle(
final boolean[][] a, final long from, final long to, final Random random) {
for (long i = to - from; i-- != 0; ) {
final long p = (random.nextLong() & 0x7FFFFFFFFFFFFFFFL) % (i + 1);
final boolean t = get(a, from + i);
set(a, from + i, get(a, from + p));
set(a, from + p, t);
}
return a;
}
