<?php
function snake($k,$y,$str1,$str2){
$x = $y - $k;
while($x < mb_strlen($str1) && $y < mb_strlen($str2) && $str1[$x] == $str2[$y]){
$x++;
$y++;
}
return $y;
}
function edit_distance_onp($str1, $str2){
$s1 = mb_strlen($str1) > mb_strlen($str2) ? $str2 : $str1;
$s2 = mb_strlen($str1) > mb_strlen($str2) ? $str1 : $str2;
$fp = array();
$x = 0;
$y = 0;
$k = 0;
$p = 0;
$offset = mb_strlen($s1) + 1;
$delta = mb_strlen($s2) - mb_strlen($s1);
for ($i = 0; $i < 100; $i++)
$fp[$i] = -1;
for ($p = 0; $fp[$delta + $offset] != mb_strlen($s2); $p++) {
for($k = -$p; $k < $delta; $k++)
$fp[$k + $offset] = snake($k, max($fp[$k-1+$offset] + 1, $fp[$k+1+$offset]), $s1, $s2);
for($k = $delta + $p; $k > $delta; $k--)
$fp[$k + $offset] = snake($k, max($fp[$k-1+$offset] + 1, $fp[$k+1+$offset]), $s1, $s2);
$fp[$delta + $offset] = snake($delta, max($fp[$delta-1+$offset] + 1, $fp[$delta+1+$offset]), $s1, $s2);
}
return $delta + ($p - 1) * 2;
}
echo edit_distance_onp("qwerty","qweasd");
?>
preferences:
37.59 ms | 402 KiB | 5 Q