feat: add php solution to lc problem: No.1287 (#961)

Author: Qiu-IT

solution/1200-1299/1287.Element Appearing More Than 25% In Sorted Array/README.md

@@ -112,6 +112,24 @@ var findSpecialInteger = function (arr) {
 };
 ```
 
+### **PHP**
+
+```php 
+class Solution {
+    /**
+     * @param Integer[] $arr
+     * @return Integer
+     */
+    function findSpecialInteger($arr) {
+        $len = count($arr);
+        for ($i = 0; $i < $len; $i++) {
+            if ($arr[$i] == $arr[$i + ($len >> 2)]) return $arr[$i];
+        }
+        return -1;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1200-1299/1287.Element Appearing More Than 25% In Sorted Array/README_EN.md

@@ -107,6 +107,24 @@ var findSpecialInteger = function (arr) {
 };
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $arr
+     * @return Integer
+     */
+    function findSpecialInteger($arr) {
+        $len = count($arr);
+        for ($i = 0; $i < $len; $i++) {
+            if ($arr[$i] == $arr[$i + ($len >> 2)]) return $arr[$i];
+        }
+        return -1;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1200-1299/1287.Element Appearing More Than 25% In Sorted Array/Solution.php

@@ -0,0 +1,13 @@
+class Solution {
+    /**
+     * @param Integer[] $arr
+     * @return Integer
+     */
+    function findSpecialInteger($arr) {
+        $len = count($arr);
+        for ($i = 0; $i < $len; $i++) {
+            if ($arr[$i] == $arr[$i + ($len >> 2)]) return $arr[$i];
+        }
+        return -1;
+    }
+}