feat: add php solution to lc problem: No.1394 (#978)

Author: Qiu-IT

solution/1300-1399/1394.Find Lucky Integer in an Array/README.md

@@ -139,6 +139,28 @@ func findLucky(arr []int) int {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $arr
+     * @return Integer
+     */
+    function findLucky($arr) {
+        $max = -1;
+        for ($i = 0; $i < count($arr); $i++) {
+            $hashtable[$arr[$i]] += 1;
+        }
+        $keys = array_keys($hashtable);
+        for ($j = 0; $j < count($keys); $j++) {
+            if ($hashtable[$keys[$j]] == $keys[$j]) $max = max($max, $keys[$j]);
+        }
+        return $max;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1300-1399/1394.Find Lucky Integer in an Array/README_EN.md

@@ -115,6 +115,28 @@ func findLucky(arr []int) int {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $arr
+     * @return Integer
+     */
+    function findLucky($arr) {
+        $max = -1;
+        for ($i = 0; $i < count($arr); $i++) {
+            $hashtable[$arr[$i]] += 1;
+        }
+        $keys = array_keys($hashtable);
+        for ($j = 0; $j < count($keys); $j++) {
+            if ($hashtable[$keys[$j]] == $keys[$j]) $max = max($max, $keys[$j]);
+        }
+        return $max;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1300-1399/1394.Find Lucky Integer in an Array/Solution.php

@@ -0,0 +1,17 @@
+class Solution {
+    /**
+     * @param Integer[] $arr
+     * @return Integer
+     */
+    function findLucky($arr) {
+        $max = -1;
+        for ($i = 0; $i < count($arr); $i++) {
+            $hashtable[$arr[$i]] += 1;
+        }
+        $keys = array_keys($hashtable);
+        for ($j = 0; $j < count($keys); $j++) {
+            if ($hashtable[$keys[$j]] == $keys[$j]) $max = max($max, $keys[$j]);
+        }
+        return $max;
+    }
+}