function GenerateGroup($ingroup, $boys, $girls)
{
$minboys = 2;
$mingirls = 1;
$output = 0;
if ($boys < 4 || $girls < 1) {
$output = 0;
} else {
$pos_combinations = BoysGirlsPossibleCombinations($ingroup, $minboys, $mingirls, $boys, $girls);
PrintArray($pos_combinations);
$sum = 0;
foreach ($pos_combinations as $combination) {
$set_combi = nCr($boys, $combination['boy']) * nCr($girls, $combination['girl']);
$sum += $set_combi;
//echo '$sum: '.$sum;
//echo "nCr($boys,".$combination['boy'].")*nCr($girls,".$combination['girl'].")<br/>";
}
$output = $sum;
}
return $output;
}
function nCr($n, $r)
{
if ($r > $n) {
return NaN;
}
if ($n - $r < $r) {
return nCr($n, $n - $r);
}
$return = 1;
for ($i = 0; $i < $r; $i++) {
$return *= ($n - $i) / ($i + 1);
}
return $return;
}
function binomialpdf($N, $p, $x)
{
return nCr($N, $x) * pow($p, $x) * pow(1 - $p, $N - $x);
}