相似度计算方法 similar_text计算会存在中英文混合的时候不准确的情况

src/Library/LCS.php

@@ -0,0 +1,83 @@
+<?php
+/**
+ * 相似度算法
+ *
+ * $lcs = new LCS();
+ * 返回最长公共子序列
+ * echo $lcs->getLCS("吉林宝源丰禽业公司","吉林业公司");
+ * echo "<br/>";
+ * //返回相似度
+ * echo $lcs->getSimilar("吉林宝源丰禽业公司","吉林业公司");
+ */
+namespace Qii\Library;
+
+class LCS
+{
+    var $str1;
+    var $str2;
+    var $c = array();
+    /*
+      返回串一和串二的最长公共子序列
+   */
+    public function getLCS($str1, $str2, $len1 = 0, $len2 = 0) {
+        $this->str1 = $str1;
+        $this->str2 = $str2;
+        if ($len1 == 0) $len1 = strlen($str1);
+        if ($len2 == 0) $len2 = strlen($str2);
+        $this->initC($len1, $len2);
+        return $this->printLCS($this->c, $len1 - 1, $len2 - 1);
+    }
+    /*
+      返回两个串的相似度
+   */
+    public function getSimilar($str1, $str2) {
+        $len1 = strlen($str1);
+        $len2 = strlen($str2);
+        $len = strlen($this->getLCS($str1, $str2, $len1, $len2));
+        return $len * 2 / ($len1 + $len2);
+    }
+
+    /**
+     * 将内容转成字符串
+     *
+     * @param int $len1 长度1
+     * @param int $len2 长度2
+     */
+    protected function initC($len1, $len2) {
+        for ($i = 0; $i < $len1; $i++) $this->c[$i][0] = 0;
+        for ($j = 0; $j < $len2; $j++) $this->c[0][$j] = 0;
+        for ($i = 1; $i < $len1; $i++) {
+            for ($j = 1; $j < $len2; $j++) {
+                if ($this->str1[$i] == $this->str2[$j]) {
+                    $this->c[$i][$j] = $this->c[$i - 1][$j - 1] + 1;
+                } else if ($this->c[$i - 1][$j] >= $this->c[$i][$j - 1]) {
+                    $this->c[$i][$j] = $this->c[$i - 1][$j];
+                } else {
+                    $this->c[$i][$j] = $this->c[$i][$j - 1];
+                }
+            }
+        }
+    }
+
+    /**
+     * 返回子串是否一致
+     *
+     * @param $c
+     * @param $i
+     * @param $j
+     * @return string
+     */
+    protected function printLCS($c, $i, $j) {
+        if ($i == 0 || $j == 0) {
+            if ($this->str1[$i] == $this->str2[$j]) return $this->str2[$j];
+            else return "";
+        }
+        if ($this->str1[$i] == $this->str2[$j]) {
+            return $this->printLCS($this->c, $i - 1, $j - 1).$this->str2[$j];
+        } else if ($this->c[$i - 1][$j] >= $this->c[$i][$j - 1]) {
+            return $this->printLCS($this->c, $i - 1, $j);
+        } else {
+            return $this->printLCS($this->c, $i, $j - 1);
+        }
+    }
+}