添加206.反转链表javaScript版本

problems/0206.翻转链表.md

@@ -147,6 +147,61 @@ Python：
 
 Go：
 
+javaScript: 
+
+```js
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+
+// 双指针：
+var reverseList = function(head) {
+    if(!head || !head.next) return head;
+    let temp = null, pre = null, cur = head;
+    while(cur) {
+        temp = cur.next;
+        cur.next = pre;
+        pre = cur;
+        cur = temp;
+    }
+    // temp = cur = null;
+    return pre;
+};
+
+// 递归：
+var reverse = function(pre, head) {
+    if(!head) return pre;
+    const temp = head.next;
+    head.next = pre;
+    pre = head
+    return reverse(pre, temp);
+}
+
+var reverseList = function(head) {
+    return reverse(null, head);
+};
+
+// 递归2
+var reverse = function(head) {
+    if(!head || !head.next) return head;
+    // 从后往前翻
+    const pre = reverse(head.next);
+    head.next = pre.next;
+    pre.next = head;
+    return head;
+}
+
+var reverseList = function(head) {
+    let cur = head;
+    while(cur && cur.next) {
+        cur = cur.next;
+    }
+    reverse(head);
+    return cur;
+};
+```
+