feat: add php solution to lc problem: No.1464 (doocs#1019)

Author: Qiu-IT

solution/1400-1499/1464.Maximum Product of Two Elements in an Array/README.md

@@ -300,6 +300,28 @@ impl Solution {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer
+     */
+    function maxProduct($nums) {
+        $max = 0;
+        $submax = 0;
+        for ($i = 0; $i < count($nums); $i++) {
+            if ($nums[$i] > $max) {
+                $submax = $max;
+                $max = $nums[$i];
+            } else if ($nums[$i] > $submax) $submax = $nums[$i];
+        }
+        return ($max - 1) * ($submax - 1);
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1400-1499/1464.Maximum Product of Two Elements in an Array/README_EN.md

@@ -275,6 +275,28 @@ impl Solution {
 }
 ```
 
+### **PHP**
+
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer
+     */
+    function maxProduct($nums) {
+        $max = 0;
+        $submax = 0;
+        for ($i = 0; $i < count($nums); $i++) {
+            if ($nums[$i] > $max) {
+                $submax = $max;
+                $max = $nums[$i];
+            } else if ($nums[$i] > $submax) $submax = $nums[$i];
+        }
+        return ($max - 1) * ($submax - 1);
+    }
+}
+```
+
 ### **...**
 
 ```

solution/1400-1499/1464.Maximum Product of Two Elements in an Array/Solution.php

@@ -0,0 +1,17 @@
+class Solution {
+    /**
+     * @param Integer[] $nums
+     * @return Integer
+     */
+    function maxProduct($nums) {
+        $max = 0;
+        $submax = 0;
+        for ($i = 0; $i < count($nums); $i++) {
+            if ($nums[$i] > $max) {
+                $submax = $max;
+                $max = $nums[$i];
+            } else if ($nums[$i] > $submax) $submax = $nums[$i];
+        }
+        return ($max - 1) * ($submax - 1);
+    }
+}