Out of sequence numbers

Hi all I have a set of numbers in order and wish to check if they are out sequence then display the range of numbers which are missing


input = 1,2,3,4,8

should output 5 6 7 or 5 > 7
what whould i need to do in php to get the output ?

 

$input = '2,3,4,8';
$numbers = explode(',', $input);
$check = 0;
for ($i = 1; $i <= $numbers[count($numbers) - 1]; $i++) {
  if ($numbers[$check] < $i) $check++;
  if ($numbers[$check] > $i) echo "$i ";
}

PHP:

Should (didn't test it) output:
1 5 6 7

 

If you put the numbers into an array, why not just asort the array?

$numbers = "1,4,7,2,14";
$sort = explode(",",$numbers);
asort($sort);
foreach($sort as $number) {
    print $number."<br />";
}

PHP:

Should output...
1
2
4
7
14

 

<?php

/**
 * @author Jay Gilford
 */

$input = '2,4,6,8,16,18,20,28';

$arr = explode(',', $input);
sort($arr);

$out = array();
$array_items = count($arr);
$lower = $arr[0];
$upper = $arr[$array_items - 1];

$difference = $upper;

for($i = 1; $i < $array_items; $i++) {
    $diff = $arr[$i] - $arr[$i - 1];
    if($diff < $difference) $difference = $diff;
}

for($i = $lower; $i < $upper; $i += $difference) {
    if(in_array($i,$arr) === false) $out[] = $i;
}
echo '<pre>'.print_r($out, true).'</pre>';

PHP:

This will work out the lowest difference between items and find the missing elements and store them in the array $out

@yourlistonline - He's already got the numbers in order, he's trying to find the missing numbers in the sequence