Levenshtein distance/Alignment: Difference between revisions

=={{header|Tcl}}==

{{tcllib|struct::list}}

<lang tcl>package require struct::list

proc levenshtein/align {a b} {

lassign [struct::list longestCommonSubsequence [split $a ""] [split $b ""]]\

apos bpos

set c ""

set d ""

set x0 [set y0 -1]

set dx [set dy 0]

foreach x $apos y $bpos {

if {$x+$dx < $y+$dy} {

set n [expr {($y+$dy)-($x+$dx)}]

incr dx $n

append c [string repeat "-" $n]

} elseif {$x+$dx > $y+$dy} {

set n [expr {($x+$dx)-($y+$dy)}]

incr dy $n

append d [string repeat "-" $n]

}

append c [string range $a $x0+1 $x]

set x0 $x

append d [string range $b $y0+1 $y]

set y0 $y

}

append c [string range $a $x0+1 end]

append d [string range $b $y0+1 end]

set al [string length $a]

set bl [string length $b]

if {$al+$y0 < $bl+$x0} {

append c [string repeat "-" [expr {$bl+$x0-$y0-$al}]]

} elseif {$bl+$x0 < $al+$y0} {

append d [string repeat "-" [expr {$al+$y0-$x0-$bl}]]

}

return $c\n$d

}

puts [levenshtein/align "rosettacode" "raisethysword"]</lang>

{{out}}

<pre>

r-oset-taco-de

raisethysword-

</pre>