function fractiondiffdrands($min, $max, $n)
{
$ds = diffrands($min, $max, $n);
$out = array();
foreach ($ds as $d) {
$out[] = fractionrand($d);
}
return $out;
}
function getprimes($n, $digits = 0)
{
global $primes;
$out = array();
if ($digits == 0) {
$c1 = count($primes[1]);
$c2 = count($primes[2]);
$c3 = count($primes[3]);
$c4 = count($primes[4]);
$c5 = count($primes[5]);
$c6 = count($primes[6]);
$locs = diffrands(0, $c1 + $c2 + $c3 + $c4 + $c5 + $c6 - 1, $n);
} else {
if ($digits < 0 || $digits > 6) {
echo "{$digits} digit primes not supported.";
return array();
} else {
$locs = diffrands(0, count($primes[$digits]) - 1, $n);
}
}
foreach ($locs as $r) {
if ($digits == 0) {
if ($r < $c1) {
$out[] = $primes[1][$r];
} else {
if ($r < $c1 + $c2) {
$out[] = $primes[2][$r - $c1];
} else {
if ($r < $c1 + $c2 + $c3) {
$out[] = $primes[3][$r - $c1 - $c2];
} else {
if ($r < $c1 + $c2 + $c3 + $c4) {
$out[] = $primes[4][$r - $c1 - $c2 - $c3];
} else {
if ($r < $c1 + $c2 + $c3 + $c4 + $c5) {
$out[] = $primes[5][$r - $c1 - $c2 - $c3 - $c4];
} else {
$out[] = $primes[6][$r - $c1 - $c2 - $c3 - $c4 - $c5];
}
}
}
}
}
} else {
$out[] = $primes[$digits][$r];
}
}
return $out;
}
function graphschedulemultchoice($g, $t, $L, $p)
{
$sc = graphlistprocessing($g, $t, $L, $p);
$tocomp = serialize($sc);
$n = count($L) - 1;
$out = array($sc);
$found = 0;
for ($cnt = 0; $cnt < 20 && $found < 4; $cnt++) {
$pl = diffrands(0, $n - 1, $n);
$pl[] = $n;
$newsc = graphlistprocessing($g, $t, $pl, $p);
if (serialize($newsc) != $tocomp) {
$found++;
$out[] = $newsc;
}
}
//echo "its: $cnt, found: $found<br/>";
return $out;
}
function matrixrandunreduce($m, $c)
{
$n = count($m);
for ($i = 0; $i < $c; $i++) {
$r = diffrands(0, $n - 1, 3);
$m = matrixrowcombine3($m, $r[0], -1, $r[1], 1, $r[2], 2, $r[0]);
}
for ($i = 0; $i < $c; $i++) {
list($sr, $er) = diffrands(0, $n - 1, 2);
$m = matrixrowswap($m, $sr, $er);
}
$c = 0;
while (hasallzerorow($m) && $c < 20) {
$r = diffrands(0, $n - 1, 3);
$m = matrixrowcombine3($m, $r[0], -2, $r[1], 1, $r[2], 3, $r[0]);
$c++;
}
return $m;
}
function chem_getdiffrandcompounds($c, $type = "twobasic,twosub,threeplus,parens")
{
global $chem_compounds;
$types = explode(',', $type);
$n = array();
foreach ($types as $v) {
$n[] = count($chem_compounds[$v]);
}
$r = diffrands(0, array_sum($n) - 1, $c);
$out = array();
foreach ($types as $i => $v) {
foreach ($r as $k => $rv) {
if ($rv < $n[$i]) {
$out[] = $chem_compounds[$v][$rv];
unset($r[$k]);
} else {
$r[$k] -= $n[$i];
}
}
}
return $out;
}
function randnames($n = 1, $gender = 2)
{
global $namearray;
if ($n == 1) {
if ($gender == 2) {
$gender = rand(0, 1);
}
return $namearray[$gender][rand(0, 137)];
} else {
$out = array();
$locs = diffrands(0, 137, $n);
for ($i = 0; $i < $n; $i++) {
if ($gender == 2) {
$gender = rand(0, 1);
}
$out[] = $namearray[$gender][$locs[$i]];
}
return $out;
}
}
