解题思路：

/*** Definition for singly-linked list.* public class ListNode {* int val;* ListNode next;* ListNode(int x) {* val = x;* next = null;* }* }*/
public class Solution {public ListNode getIntersectionNode(ListNode headA, ListNode headB) {if (headA == null || headB == null) return null;ListNode pa = headA;ListNode pb = headB;while (pa != pb) {pa = (pa != null) ? pa.next : headB;pb = (pb != null) ? pb.next : headA;if (pa == null && pb == null) return null;}return pa;}
}