Shell Programming and Scripting

awk '{if(s==$1&&p+1==$2){v[++j]=p;t=1}else if(t){print s,v[1],p;j=t=0}p=$2;s=$1}' input_file

3 00
3 01
3 02
3 07
3 09
3 10
3 15
3 16
3 17
3 18
3 40
3 45
3 500
3 501
3 502
3 70
3 80

#! /usr/bin/perl -w
use strict;
my ($i, @x, $prev);
open I, "< input";
$i=1;
for (<I>) {
    @x = split /\s+/, $_;
    if ($i == 1) {
        $prev = $x[1];
        printf "3 %02d ", $x[1];
        $i++;
        next;
    }
    else {
        if ($x[1] == $prev + 1) {
            $prev = $x[1];
            ($i == $.) && printf "%02d\n", $x[1];
            $i++;
            next;
        }
        else {
            printf "%02d\n", $prev;
            printf "3 %02d ", $x[1];
            ($i == $.) && printf "%02d\n", $x[1];
            $prev = $x[1];
            $i++;
        }
    }
}
close I;

3 00 02
3 07 07
3 09 10
3 15 18
3 40 40
3 45 45
3 500 502
3 70 70
3 80 80

#!/bin/bash
input=$1
awk '{a[++j]=$2;b[j]=$1}
END{
  for(i=1;i<=j;i++){
   if(a[i+1]-a[i]==1 && b[i]==b[i+1]){
     a[i]==0?s="00":0;!s?s=a[i]:0;continue
   } print b[i],!s?a[i]:s,a[i];s=0 }
}' $input

root@bt:/tmp# ./run input_file
3 00 02
3 07 07
3 09 10
3 15 18
3 40 40
3 45 45
3 500 502
3 70 70
3 80 80