vault backup: 2022-06-15 22:32:23

CS notes/pages/Leetcode Reverse-Linked-List.md

@@ -4,7 +4,7 @@
 
 ---
 ##### Algorithms:
-#algorithm #recursion 
+#algorithm #recursion #iteration 
 ##### Data structures:
 #DS #linked_list 
 ##### Difficulty:
@@ -17,15 +17,39 @@ tag:#linked_list
  
 
 ##### Links:
-- [Link to problem]()
+- [Link to problem](https://leetcode.com/problems/reverse-linked-list/)
 ___
 ### Problem
-
+Given the `head` of a singly linked list, reverse the list, and return _the reversed list_.
 #### Examples
+**Example 1:**
+
+![](https://assets.leetcode.com/uploads/2021/02/19/rev1ex1.jpg)
+
 ```markdown
+**Input:** head = [1,2,3,4,5]
+**Output:** [5,4,3,2,1]
+```
+
+**Example 2:**
+
+![](https://assets.leetcode.com/uploads/2021/02/19/rev1ex2.jpg)
+
+```markdown
+**Input:** head = [1,2]
+**Output:** [2,1]
+```
+
+**Example 3:**
+
+```markdown
+**Input:** head = []
+**Output:** []
 ```
 
 #### Constraints
+-   The number of nodes in the list is the range `[0, 5000]`.
+-   `-5000 <= Node.val <= 5000`
 
 ### Thoughts