## Problem Statement
Given the beginning of a singly linked list `head`, reverse the list, and return the new beginning of the list.
<ins>Example 1:</ins>
```text
Input: head = [0,1,2,3]
Output: [3,2,1,0]
```
<ins>Example 2:</ins>
```text
Input: head = []
Output: []
```
## Solution
```python
# Definition for singly-linked list.
# class ListNode:
# def __init__(self, val=0, next=None):
# self.val = val
# self.next = next
class Solution:
def reverseList(self, head: Optional[ListNode]) -> Optional[ListNode]:
prev, cur = None, head
while cur is not None:
# store next
nxt = cur.next
# reverse node
cur.next = prev
# increment pointers
prev = cur
cur = nxt
return prev
```
## Notes