这题要注意就是,当先遍历完的链表接下来遍历另外一个链表,如果两个链表有相交,则两个指针会重合
时间复杂度 O(n^2)
/**
* Definition for singly-linked list.
* function ListNode(val) {
* this.val = val;
* this.next = null;
* }
*/
/**
* @param {ListNode} headA
* @param {ListNode} headB
* @return {ListNode}
*/
var getIntersectionNode = function (headA, headB) {
if (!headA || !headB) return null;
let pA = headA;
let pB = headB;
while (pA !== pB) {
pA = pA ? pA.next : headB
pB = pB ? pB.next : headA
}
return pA;
};