题解 | #链表中倒数最后k个结点#

/*class ListNode {
 *     val: number
 *     next: ListNode | null
 *     constructor(val?: number, next?: ListNode | null) {
 *         this.val = (val===undefined ? 0 : val)
 *         this.next = (next===undefined ? null : 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
 */
export function FindKthToTail(pHead: ListNode, k: number): ListNode {
    // write code here
    let map = {}, len = 0, cur = pHead
    while(cur) {
        map[len++] = cur
        cur = cur.next
    }
    return len - k >= 0 ? map[len - k] : null
}