面试题 02.02. 返回倒数第 k 个节点 - 力扣（LeetCode）
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* struct ListNode *next;
* };
*/
int kthToLast(struct ListNode* head, int k)
{
struct ListNode* fastnode = head;
struct ListNode* slownode = head;
while(k--)
{
fastnode = fastnode->next;
}
while(fastnode)
{
fastnode = fastnode->next;
slownode = slownode->next;
}
return slownode->val;
}