题目描述

输入一个链表，输出该链表中倒数第k个结点。

/*
struct ListNode {
    int val;
    struct ListNode *next;
    ListNode(int x) :
            val(x), next(NULL) {
    }
};*/
class Solution {
public:
    ListNode* FindKthToTail(ListNode* pListHead, unsigned int k) {
        ListNode* pre = pListHead;
        ListNode* back = pListHead;
        int count = 0;
        while(pre != nullptr) {
            if(count < k)
                ++count;
            else
                back = back->next;
            pre = pre->next;
        }
        return count < k ? nullptr : back;
    }
};