[剑指offer]面试题15.链表中倒数第K个节点

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) {        if(pListHead == NULL)            return NULL;        ListNode* fast = pListHead;        ListNode* slow = pListHead;        while(k--){            if(fast)                fast = fast->next;            else                return NULL;        }        while(fast != NULL){            fast = fast->next;            slow = slow->next;        }        return slow;    }};