$/=$\;$_=<>;
1while s/(.)\1/$1 $1/;
s/^|\B|$/|/mg;
/.+/;
$m='-'x($L=length$&);
s/^/$m\n/mg;s/$/\n$m/;
1while s/((\w).{$L})-(.{$L}\2)/$1 $3/sg
||s/ - / /g
||s/^- | -$/ /m
||s/\|.{$L}\K-|-(?=.{$L}\|)/+/gs
||s/(\|.{$L}) (.{$L}\|)/$1|$2/sg;
print
Note that non-ascii characters in the above source code will be escaped (such as \x9f).