添加 0203.移除链表元素 PHP版本

problems/0203.移除链表元素.md

@@ -331,8 +331,32 @@ func removeElements(_ head: ListNode?, _ val: Int) -> ListNode? {
 }
 ```
 
-
-
+PHP:
+```php
+/**
+ * Definition for singly-linked list.
+ * type ListNode struct {
+ *     Val int
+ *     Next *ListNode
+ * }
+ */
+ // 虚拟头+双指针
+func removeElements(head *ListNode, val int) *ListNode {
+    dummyHead := &ListNode{}
+    dummyHead.Next = head
+    pred := dummyHead
+    cur := head
+    for cur != nil {
+        if cur.Val == val {
+            pred.Next = cur.Next
+        } else {
+            pred = cur
+        }
+        cur = cur.Next
+    }
+    return dummyHead.Next
+}
+```
 
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 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)