PHP改进计算字符串相似度的函数similar_text()、levenshtein()

???? <?php?
???? //拆分字符串?
???? function split_str($str) {?
?????? preg_match_all("/./u",$str,$arr);?
?????? return $arr[0];?
???? }?
??????
???? //相似度检测?
???? function similar_text_cn($str1,$str2) {?
?????? $arr_1 = array_unique(split_str($str1));?
?????? $arr_2 = array_unique(split_str($str2));?
?????? $similarity = count($arr_2) - count(array_diff($arr_2,$arr_1));?
????????
?????? return $similarity;?
???? }??

???? <?php?
???? //拆分字符串?
???? function mbStringToArray($string,$encoding = 'UTF-8') {?
???????? $arrayResult = array();?
???????? while ($iLen = mb_strlen($string,$encoding)) {?
???????????? array_push($arrayResult,mb_substr($string,1,$encoding));?
???????????? $string = mb_substr($string,$iLen,$encoding);?
???????? }?
???????? return $arrayResult;?
???? }?
???? //编纂距离?
???? function levenshtein_cn($str1,$str2,$costReplace = 1,$encoding = 'UTF-8') {?
???????? $count_same_letter = 0;?
???????? $d = array();?
???????? $mb_len1 = mb_strlen($str1,$encoding);?
???????? $mb_len2 = mb_strlen($str2,$encoding);?
???????? $mb_str1 = mbStringToArray($str1,$encoding);?
???????? $mb_str2 = mbStringToArray($str2,$encoding);?
???????? for ($i1 = 0; $i1 <= $mb_len1; $i1++) {?
???????????? $d[$i1] = array();?
???????????? $d[$i1][0] = $i1;?
???????? }?
???????? for ($i2 = 0; $i2 <= $mb_len2; $i2++) {?
???????????? $d[0][$i2] = $i2;?
???????? }?
???????? for ($i1 = 1; $i1 <= $mb_len1; $i1++) {?
???????????? for ($i2 = 1; $i2 <= $mb_len2; $i2++) {?
???????????????? // $cost = ($str1[$i1 - 1] == $str2[$i2 - 1]) ? 0 : 1;?
???????????????? if ($mb_str1[$i1 - 1] === $mb_str2[$i2 - 1]) {?
???????????????????? $cost = 0;?
???????????????????? $count_same_letter++;?
???????????????? } else {?
???????????????????? $cost = $costReplace; //替换?
???????????????? }?
???????????????? $d[$i1][$i2] = min($d[$i1 - 1][$i2] + 1,//插入?
???????????????? $d[$i1][$i2 - 1] + 1,//删除?
???????????????? $d[$i1 - 1][$i2 - 1] + $cost);?
???????????? }?
???????? }?
???????? return $d[$mb_len1][$mb_len2];?
???????? //return array('distance' => $d[$mb_len1][$mb_len2],'count_same_letter' => $count_same_letter);?
???? }??

???????? <?php?
???????? //最长公共子序列英文版?
???????? function LCS_en($str_1,$str_2) {?
?????????? $len_1 = strlen($str_1);?
?????????? $len_2 = strlen($str_2);?
?????????? $len = $len_1 > $len_2 ? $len_1 : $len_2;?
?????????? $dp = array();?
?????????? for ($i = 0; $i <= $len; $i++) {?
???????????? $dp[$i] = array();?
???????????? $dp[$i][0] = 0;?
???????????? $dp[0][$i] = 0;?
?????????? }?
?????????? for ($i = 1; $i <= $len_1; $i++) {?
???????????? for ($j = 1; $j <= $len_2; $j++) {?
?????????????? if ($str_1[$i - 1] == $str_2[$j - 1]) {?
???????????????? $dp[$i][$j] = $dp[$i - 1][$j - 1] + 1;?
?????????????? } else {?
???????????????? $dp[$i][$j] = $dp[$i - 1][$j] > $dp[$i][$j - 1] ? $dp[$i - 1][$j] : $dp[$i][$j - 1];?
?????????????? }?
???????????? }?
?????????? }?
?????????? return $dp[$len_1][$len_2];?
???????? }?
???????? //拆分字符串?
???????? function mbStringToArray($string,$encoding = 'UTF-8') {?
?????????? $arrayResult = array();?
?????????? while ($iLen = mb_strlen($string,$encoding);?
?????????? }?
?????????? return $arrayResult;?
???????? }?
???????? //最长公共子序列中文版?
???????? function LCS_cn($str1,$encoding = 'UTF-8') {?
?????????? $mb_len1 = mb_strlen($str1,$encoding);?
?????????? $mb_len2 = mb_strlen($str2,$encoding);?
?????????? $mb_str1 = mbStringToArray($str1,$encoding);?
?????????? $mb_str2 = mbStringToArray($str2,$encoding);?
?????????? $len = $mb_len1 > $mb_len2 ? $mb_len1 : $mb_len2;?
?????????? $dp = array();?
?????????? for ($i = 0; $i <= $len; $i++) {?
???????????? $dp[$i] = array();?
???????????? $dp[$i][0] = 0;?
???????????? $dp[0][$i] = 0;?
?????????? }?
?????????? for ($i = 1; $i <= $mb_len1; $i++) {?
???????????? for ($j = 1; $j <= $mb_len2; $j++) {?
?????????????? if ($mb_str1[$i - 1] == $mb_str2[$j - 1]) {?
???????????????? $dp[$i][$j] = $dp[$i - 1][$j - 1] + 1;?
?????????????? } else {?
???????????????? $dp[$i][$j] = $dp[$i - 1][$j] > $dp[$i][$j - 1] ? $dp[$i - 1][$j] : $dp[$i][$j - 1];?
?????????????? }?
???????????? }?
?????????? }?
?????????? return $dp[$mb_len1][$mb_len2];?
???????? }