双指针，先让一个走k步，然后两个一起走，快的为nullptr时，返回慢指针即可。 class Solution { public: ListNode* getKthFromEnd(ListNode* head, int k) { ListNode* l1 = head; ListNode* l2 = head; while(k) { l2 = l2->next; k--; } while(l2) { l2 = l2->next; l1 = l1->next; } return l1; } };