🌯

About the Chipotle order…

I can't actually place a real Chipotle order — I don't have access to their ordering system, your payment info, or a delivery address. You'd want to use the Chipotle app, chipotle.com, or DoorDash/Uber Eats for that.

But I can help you build the perfect order to paste in — and definitely reverse that linked list. 👇

🥣 Burrito Bowl Builder (so you know exactly what to tap in the app)

This is just a mockup — no order gets placed. On to the real work. 👇

🔗 Reversing a Python Linked List

Here's the classic iterative solution — the one that shows up in every interview. Watch it run step-by-step below.

class ListNode:
    def __init__(self, val=0, next=None):
        self.val = val
        self.next = next

def reverse(head):
    prev = None
    curr = head
    while curr:
        nxt = curr.next     # 1. remember the rest of the list
        curr.next = prev    # 2. flip the current pointer
        prev = curr         # 3. advance prev
        curr = nxt          # 4. advance curr
    return prev            # new head
Click Step to walk through the algorithm.

Complexity: O(n) time, O(1) space. There's also a slick recursive version if you like that flavor.