Linked List· 15 min

Reverse Linked List

LeetCode #206 · Easy · Interactive step-by-step visualization

Setup

Example inputhead = [1, 2, 3, 4, 5]
Step 1 / 17

Current step

1 / 17

Reverse the links, not the values. Each node keeps its value; only the direction of every pointer changes. Track previous, current and the next node before any link is cut.

Step log

head

head
1
2
3
4
5
null

list

1 → 2 → 3 → 4 → 5

Named pointer
Active node
Committed or completed
Detached or removed
reverse-linked-list.java
1public ListNode reverseList(ListNode head) {
2    ListNode prev = null, curr = head;
3    while (curr != null) {
4        ListNode next = curr.next;
5        curr.next = prev;
6        prev = curr;
7        curr = next;
8    }
9    return prev;
10}
● Java
Time
O(n)
Space
O(1)
Pattern
linked list
Frames
17
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