Merge pull request #1512 from destroyerngu/master

添加0034 Kotlin版,0203 Kotlin版,0209 Koltin版, 0977 Kotlin版

problems/0203.移除链表元素.md

@@ -534,5 +534,39 @@ object Solution {
   }
 }
 ```
+Kotlin:
+```kotlin
+/**
+ * Example:
+ * var li = ListNode(5)
+ * var v = li.`val`
+ * Definition for singly-linked list.
+ * class ListNode(var `val`: Int) {
+ *     var next: ListNode? = null
+ * }
+ */
+class Solution {
+    fun removeElements(head: ListNode?, `val`: Int): ListNode? {
+        // 使用虚拟节点，令该节点指向head
+        var dummyNode = ListNode(-1)
+        dummyNode.next = head
+        // 使用cur遍历链表各个节点
+        var cur = dummyNode
+        // 判断下个节点是否为空
+        while (cur.next != null) {
+            // 符合条件，移除节点
+            if (cur.next.`val` == `val`) {
+                cur.next = cur.next.next
+            }
+            // 不符合条件，遍历下一节点
+            else {
+                cur = cur.next
+            }
+        }
+        // 注意：返回的不是虚拟节点
+        return dummyNode.next
+    }
+}
+```
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