题解 | #链表中倒数最后k个结点#

/**
 * struct ListNode {
 *  int val;
 *  struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 *
 * @param pHead ListNode类
 * @param k int整型
 * @return ListNode类
 */
struct ListNode* FindKthToTail(struct ListNode* pHead, int k ) {
    // write code here
    int n = - k;
    struct ListNode* nHead = pHead;
    while (nHead != NULL) {
        n++;
        nHead = nHead->next;
    }
    if (n < 0) {
        return NULL;
    }
    while (pHead != NULL) {
        if (n <= 0) {
            break;
        }
        n--;
        pHead = pHead->next;
    }
    return pHead;
}