http://qs321.pair.com?node_id=11118315

I suspect there is no "good and fast" solution. This problem, to me, has the flavor of a permutation or "traveling salesman" problem, and is probably NP-hard (or one of the other NP classes).

So here's an attempt (with a cheat) that at least gets a solution in a sort of reasonable time for this problem.

```#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11118281
use warnings;

my @list=("set abcde-efghi 12345",
"set abcde-ijkl 12345",
"clr abcde-efghi+123",
"clr abcde-ijkl 12345");

#my @expected_substrings=("set","clr"," abcde-","efghi",
#                         "ijkl"," 12345","+123");
#my \$len=@expected_substrings*2;
#\$len+=length(\$_) foreach @expected_substrings;

\$_ = join "\n", @list;
my \$max = 3; ########################################### BIG CHEAT FOR
+ RUNTIME

sub score { 2 * @_ + length join '', @_; }
my \$best = score( @list );

try( \$_ );
print "\n";

sub try
{
(local \$_, my @sofar) = @_;
if( !/[ -~]/ )
{
my \$score = score @sofar;
if( \$score < \$best )
{
print "\n";
use Data::Dump 'dd'; dd \$score, @sofar;
\$best = \$score;
}
return;
}
score(@sofar) >= \$best and return;
for my \$n ( reverse 0 .. \$#list )
{
my %d;
/([ -~]{3,})(?:.*?\1){\$n}(?{ \$d{\$1}++ })(*FAIL)/s;
my @d = sort { length \$b <=> length \$a } sort keys %d;
@d > \$max and \$#d = \$max - 1;
for my \$string ( @d )
{
try( s/\Q\$string\E/\t/gr, @sofar, \$string );
}
}
}
```(46, " abcde-", " 12345", "efghi", "ijkl", "clr", "set", "+123")