feat: add php solution to lc problem: No.2000 (doocs#941)

No.2000.Reverse Prefix of Word

Author: Qiu-IT

solution/2000-2099/2000.Reverse Prefix of Word/README.md

@@ -167,6 +167,34 @@ impl Solution {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param String $word
+     * @param String $ch
+     * @return String
+     */
+    function reversePrefix($word, $ch) {
+        $len = strlen($word);
+        $rs = '';
+        for ($i = 0; $i < $len; $i++) {
+            $rs = $rs.$word[$i];
+            if ($word[$i] == $ch) {
+                break;
+            }
+        }
+        if (strlen($rs) == $len && $rs[$len - 1] != $ch) {
+            return $word;
+        }
+        $rs = strrev($rs);
+        $rs = $rs.substr($word, strlen($rs));
+        return $rs;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/2000-2099/2000.Reverse Prefix of Word/README_EN.md

@@ -154,6 +154,34 @@ impl Solution {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param String $word
+     * @param String $ch
+     * @return String
+     */
+    function reversePrefix($word, $ch) {
+        $len = strlen($word);
+        $rs = '';
+        for ($i = 0; $i < $len; $i++) {
+            $rs = $rs.$word[$i];
+            if ($word[$i] == $ch) {
+                break;
+            }
+        }
+        if (strlen($rs) == $len && $rs[$len - 1] != $ch) {
+            return $word;
+        }
+        $rs = strrev($rs);
+        $rs = $rs.substr($word, strlen($rs));
+        return $rs;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/2000-2099/2000.Reverse Prefix of Word/Solution.php

@@ -0,0 +1,23 @@
+class Solution {
+    /**
+     * @param String $word
+     * @param String $ch
+     * @return String
+     */
+    function reversePrefix($word, $ch) {
+        $len = strlen($word);
+        $rs = '';
+        for ($i = 0; $i < $len; $i++) {
+            $rs = $rs.$word[$i];
+            if ($word[$i] == $ch) {
+                break;
+            }
+        }
+        if (strlen($rs) == $len && $rs[$len - 1] != $ch) {
+            return $word;
+        }
+        $rs = strrev($rs);
+        $rs = $rs.substr($word, strlen($rs));
+        return $rs;
+    }
+}