This code will accept user input from the command line.The first user can enter the limit of series.e.g: user may enter 5After that, the user will be prompted for 5 numbers of a series.e.g:2481012Here in this series, 6 is missing, so I am going to find the missing series from common difference series.I got the correct output from this code. Is it the correct way?  Is there any other simple code to do the same?<?php    fscanf(STDIN, %d\n, $count);    $series = array();    $common_diff = array();    $prev_element = null;    for($i=0;$i<$count;$i++){        fscanf(STDIN, %d\n, $series[$i]);        if($prev_element != null){            $common_diff[] = $series[$i] - $prev_element;        }        $prev_element = $series[$i];    }    $c = array_count_values($common_diff);    asort($c);    end($c);    $common_d = key($c);    $prev_element = $series[0];    $missed_no = 0;    for($i=1;$i<$count;$i++){        $diff = $series[$i] - $prev_element;        if($diff != $common_d){            $missed_no = $prev_element + $common_d;        }        $prev_element = $series[$i];    }    echo $missed_no;    exit;?>example input52481012
Finding missing number from series
php