添加 0349.两个数组的交集 PHP版本

problems/0349.两个数组的交集.md

@@ -209,6 +209,35 @@ func intersection(_ nums1: [Int], _ nums2: [Int]) -> [Int] {
 }
 ```
 
+PHP:
+```php
+class Solution {
+    /**
+     * @param Integer[] $nums1
+     * @param Integer[] $nums2
+     * @return Integer[]
+     */
+    function intersection($nums1, $nums2) {
+        if (count($nums1) == 0 || count($nums2) == 0) {
+            return [];
+        }
+        $counts = [];
+        $res = [];
+        foreach ($nums1 as $num) {
+            $counts[$num] = 1;
+        }
+        foreach ($nums2 as $num) {
+            if (isset($counts[$num])) {
+                $res[] = $num;
+            }
+            unset($counts[$num]);
+        }
+        
+        return $res;
+    }
+}
+```
+
 ## 相关题目
 
 * 350.两个数组的交集 II