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<?php
// Simple seeded random number generator
// Credits for the mechanism:
// http://www.sitepoint.com/php-random-number-generator/
function seeded_random($seed, $min, $max) {
$seed = ($seed * 125) % 2796203;
$res = $seed % ($max - $min + 1) + $min;
return Array($res, $seed);
}
// Shuffle function
function seeded_shuffle($ar, $seed) {
$c = count($ar);
$tmp = $ar;
$se = $seed;
for($i=0;$i<$c;$i++) {
$r = seeded_random($se, 0, (count($ar) - 1));
$num = $r[0];
$se = $r[1];
// Swap
$t = $tmp[$i];
$tmp[$i] = $tmp[$num];
$tmp[$num] = $t;
}
return $tmp;
}
// Example
// Call of seeded_shuffle with same array and same seed will always
// return the same shuffled array
$example_data = Array("First", "Second", "Third");
$shuffled = seeded_shuffle($example_data, 12345);
print_r($shuffled);
// Array ( [0] => Second [1] => Third [2] => First )
?>
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