876-链表的中间结点 ​

function middleNode(head: ListNode | null): ListNode | null {
  let slow = head
  let fast = head

  // 快指针每次走两步
  // 满指针每次走一步
  while (fast && fast.next) {
    slow = slow.next
    fast = fast.next.next
  }

  return slow
}

function middleNode(head: ListNode | null): ListNode | null {
  let slow = head
  let fast = head

  // 快指针每次走两步
  // 满指针每次走一步
  while (fast && fast.next) {
    slow = slow.next
    fast = fast.next.next
  }

  return slow
}