From 4f5ebdabca741e124269cb5d139eaf816b5e8f4a Mon Sep 17 00:00:00 2001
From: reoooh <reoooh@hotmail.com>
Date: Sun, 1 Aug 2021 00:01:37 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A00206=E7=BF=BB=E8=BD=AC?=
 =?UTF-8?q?=E9=93=BE=E8=A1=A8=20Ruby=20=E7=89=88=E6=9C=AC?=
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---
 problems/0206.翻转链表.md | 43 +++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/problems/0206.翻转链表.md b/problems/0206.翻转链表.md
index 963d7916..4efdda3b 100644
--- a/problems/0206.翻转链表.md
+++ b/problems/0206.翻转链表.md
@@ -275,7 +275,50 @@ var reverseList = function(head) {
 };
 ```
 
+Ruby:
 
+```ruby
+# 双指针
+# Definition for singly-linked list.
+# class ListNode
+#     attr_accessor :val, :next
+#     def initialize(val = 0, _next = nil)
+#         @val = val
+#         @next = _next
+#     end
+# end
+def reverse_list(head)
+  # return nil if head.nil?	# 循环判断条件亦能起到相同作用因此不必单独判断
+  cur, per = head, nil
+  until cur.nil?
+    tem = cur.next
+    cur.next = per
+    per = cur
+    cur = tem
+  end
+  per
+end
+
+# 递归
+# Definition for singly-linked list.
+# class ListNode
+#     attr_accessor :val, :next
+#     def initialize(val = 0, _next = nil)
+#         @val = val
+#         @next = _next
+#     end
+# end
+def reverse_list(head)
+  reverse(nil, head)
+end
+
+def reverse(pre, cur)
+  return pre if cur.nil?
+  tem = cur.next
+  cur.next = pre
+  reverse(cur, tem)	# 通过递归实现双指针法中的更新操作
+end
+```
 
 
 -----------------------