关关的刷题日记75 – Leetcode 160. Intersection of Two Linked Lists

class Solution {
public:
    ListNode *getIntersectionNode(ListNode *headA, ListNode *headB) {
        int count1=0, count2=0;
        ListNode *p1, *p2;
        p1=headA;
        p2=headB;
        while(p1!=nullptr)
        {
            count1++;
            p1=p1->next;
        }
        while(p2!=nullptr)
        {
            count2++;
            p2=p2->next;
        }
        if(count1 < count2)
        {
            for(int i=1; i<=count2-count1; i++)
                headB=headB->next;
        }
        else
        {
            for(int i=1; i<=count1-count2; i++)
                headA=headA->next;
        }
        while(headA!=nullptr && headB!=nullptr)
        {
            if(headA==headB)
                return headA;
            headA=headA->next;
            headB=headB->next;
        }
        return nullptr;
    }
};