get_missed_number
1234567891011121314151617181920
<?php
$numbers=array(1,4,7,13);
function get_missed_number($sequence)
{
if(count($sequence)<2) { return false; }
elseif(count($sequence)==2) { return ($sequence[1]-$sequence[0])/2; }
else
{
$pDiff=$sequence[1]-$sequence[0];
for($i=1;$i<count($sequence);$i++)
{
if(($sequence[$i+1]-$sequence[$i])>$pDiff)
{
return $sequence[$i]+(($sequence[$i+1]-$sequence[$i])/2);
};
};
};
}
echo(get_missed_number($numbers));
Php
INFO