#! perl -slw
use strict;
use Data::Dump qw[ pp ];

## Generate some data
my $string = '1234567890' x 7;
my @bits = map[ int rand length $string, 2 + int rand 10 ], 1 .. 20;

## Sort ascending offset/descending length
@bits = sort{
    $a->[ 0 ] <=> $b->[ 0 ]
    ||
    $b->[ 1 ] <=> $a->[ 1 ]
} @bits;

## build groups
my @groups;

## Till done
while( @bits ) {
    ## start a new group with the last bit
    push @groups, [  pop @bits ];

    ## Scan the rest of the bits (backward so we can splice without bad kharma)
    for my $bit ( reverse 0 .. $#bits ) {
        ## if it'll fit in this line
        if( $bits[ $bit ][ 0 ]+ $bits[ $bit ][ 1 ] < $groups[-1][-1][0] ) {
             ## add it
            push @{ $groups[-1] }, splice @bits, $bit, 1;
        }
    }
}

## display the results
print $string;
for my $group ( @groups ){
    my $line = ' ' x 70;
    for my $bit ( @{ $group } ) {
        substr $line, $bit->[ 0 ], $bit->[ 1 ], 
            substr $string, $bit->[ 0 ], $bit->[ 1 ];
    }
    print $line;
}

__END__
c:\test>700817.pl
1234567890123456789012345678901234567890123456789012345678901234567890
 23    89    4567890    567890123     9012  567890123      012       0
           234567890    56789012345   901234567                45678
          123456789    45678    3456789012               890123
        90123456      3456789
                     234
                  90123456

c:\test>700817.pl
1234567890123456789012345678901234567890123456789012345678901234567890
           2345  890123  6789012  5678   234567  012345      2345   90
    5678901234  789012345     12345          67890123      01234    90
   45678901    6789                      234567890            34567
                                       0123456789         9012345

c:\test>700817.pl
1234567890123456789012345678901234567890123456789012345678901234567890
                    1234567     34567    234567890        9012       0
            345678901   5678901    6789012               89012  567890
                     23456789012  567890                     234567890
             4567890123   789012345                        0123456789
                        5678901234
                       45678901234
                 89012345
              56789012345

c:\test>700817.pl
1234567890123456789012345678901234567890123456789012345678901234567890
123456  90    56789012  56789     567    234567   1234       234567890
     67   123456789            23456      345678901        01234
     678901234                1234                       890
                           890123456                     89012
                         678901234                   45678901