Leetcode 剑指 Offer 52. 两个链表的第一个公共节点（DAY 257）---- 后端面试题

文章目录

• • 原题题目
  • 代码实现（首刷自解）

原题题目

代码实现（首刷自解）

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode *getIntersectionNode(ListNode *headA, ListNode *headB) {
        ListNode* ptr1 = headA,*ptr2 = headB;
        while(ptr1 && ptr2)
        {
            ptr1 = ptr1->next;
            ptr2 = ptr2->next;
        }

        ListNode* ptr_next1 = headA,*ptr_next2 = headB;
        while(ptr1 || ptr2)
        {
            if(ptr1)    
            {
                ptr_next1 = ptr_next1->next;
                ptr1 = ptr1->next;
            }
            else
            {
                ptr_next2 = ptr_next2->next;
                ptr2 = ptr2->next;
            }
        }

        while(ptr_next1 && ptr_next2 && ptr_next1 != ptr_next2)
        {
            ptr_next1 = ptr_next1->next;
            ptr_next2 = ptr_next2->next;
        }

        return ptr_next1;
    }
};