题解 | #输出单向链表中倒数第k个结点#

快慢指针

class Node {
  constructor(val, next) {
    this.val = val;
    this.next = next;
  }
}

function create(values) {
  const head = new Node(values[0], null);
  let p = head;
  for (let i = 1; i < values.length; i++) {
    let val = values[i];
    let node = new Node(val, null);
    p.next = node;
    p = node;
  }
  return head;
}

while (readline()) {
  let values = readline().split(" ");
  let head = create(values);
  let k = parseInt(readline());
  let fast = head;
  let slow = head;
  while (k > 0) {
    fast = fast.next;
    k--;
  }
  while (fast) {
    fast = fast.next;
    slow = slow.next;
  }
  print(slow.val);
}