feat: add php solution to lc problem: No.1704 (doocs#979)

Author: Qiu-IT

solution/1700-1799/1704.Determine if String Halves Are Alike/README.md

@@ -174,6 +174,25 @@ impl Solution {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param String $s
+     * @return Boolean
+     */
+    function halvesAreAlike($s) {
+        $cnt = 0;
+        for ($i = 0; $i < strlen($s) / 2; $i++) {
+            if (strpos("aeiouAEIOU", $s[$i]) !== false) $cnt++;
+            if (strpos("aeiouAEIOU", $s[strlen($s) / 2 + $i]) !== false) $cnt--;
+        }
+        return $cnt == 0;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1700-1799/1704.Determine if String Halves Are Alike/README_EN.md

@@ -158,6 +158,25 @@ impl Solution {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param String $s
+     * @return Boolean
+     */
+    function halvesAreAlike($s) {
+        $cnt = 0;
+        for ($i = 0; $i < strlen($s) / 2; $i++) {
+            if (strpos("aeiouAEIOU", $s[$i]) !== false) $cnt++;
+            if (strpos("aeiouAEIOU", $s[strlen($s) / 2 + $i]) !== false) $cnt--;
+        }
+        return $cnt == 0;
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1700-1799/1704.Determine if String Halves Are Alike/Solution.php

@@ -0,0 +1,14 @@
+class Solution {
+    /**
+     * @param String $s
+     * @return Boolean
+     */
+    function halvesAreAlike($s) {
+        $cnt = 0;
+        for ($i = 0; $i < strlen($s) / 2; $i++) {
+            if (strpos("aeiouAEIOU", $s[$i]) !== false) $cnt++;
+            if (strpos("aeiouAEIOU", $s[strlen($s) / 2 + $i]) !== false) $cnt--;
+        }
+        return $cnt == 0;
+    }
+}