[leetcode]Intersection of Two Linked Lists

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public class Solution { public ListNode getIntersectionNode(ListNode headA, ListNode headB) { if (headA == null || headB == null) return null; int lengthA = 0; ListNode runner = headA; while (runner != null){ lengthA++; runner = runner.next; } int lengthB = 0; runner = headB; while (runner != null){ lengthB++; runner = runner.next; } for (int i = 0; i < lengthA-lengthB; i++, headA = headA.next); for (int i = 0; i < lengthB-lengthA; i++, headB = headB.next); while (headA != null){ if (headA == headB) return headA; headA = headA.next; headB = headB.next; } return null; } }