题解 | #链表中倒数最后k个结点#

/*
 * function ListNode(x){
 *   this.val = x;
 *   this.next = null;
 * }
 */
/**
 * 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
 */
function FindKthToTail(pHead, k) {
    // write code here
    let list = reverseList(pHead),
        res = null,
        count = 0;

    while (list) {
        count = count + 1;
        let node = new ListNode(list.val);
        node.next = res;
        res = node;
        if (count === k) return res;
        list = list.next;
    }
    return null;
}

function reverseList(pHead) {
    let cur = pHead,
        pre = null,
        t = null;
    while (cur) {
        t = cur.next;
        cur.next = pre;
        pre = cur;
        cur = t;
    }
    return pre;
}
module.exports = {
    FindKthToTail: FindKthToTail,
};