Day3. Start Algorithm

206. Reverse Linked List/Solution.cs

@@ -0,0 +1,22 @@
+namespace _206._Reverse_Linked_List;
+
+public class Solution
+{
+    public ListNode? ReverseList(ListNode head)
+    {
+        if (head == null || head.next == null)
+            return head;
+        ListNode cur = head;
+        ListNode newHead = cur.next!;
+        cur.next = null;
+        while (true)
+        {
+            ListNode? buf = newHead.next;
+            newHead.next = cur;
+            if (buf == null)
+                return newHead;
+            cur = newHead;
+            newHead = buf;
+        }
+    }
+}