LeetCode 160. Intersection of Two Linked Lists

Question

Given the heads of two singly linked-lists headA and headB, return the node at which the two lists intersect. If the two linked lists have no intersection at all, return null.

https://leetcode.com/problems/intersection-of-two-linked-lists/

• Solution1

public class Solution {
    public ListNode getIntersectionNode(ListNode headA, ListNode headB) {
        ListNode a = headA, b = headB;
        while(a != b){
            a = a == null ? headB : a.next;
            b = b == null ? headA : b.next;
        }
        return a;
    }
}

Complexity:

Time complexity: O(n)

Space complexity: O(1)