package main

import "fmt"

type ListNode struct {
	Val  int
	Next *ListNode
}

func main() {

}
func removeNthFromEnd(head *ListNode, n int) *ListNode {
	if head.Next == nil && n == 1 {
		return nil
	}
	firstNode := (*ListNode)(nil)
	result := (*ListNode)(nil)
	preNode := (*ListNode)(nil)
	for head != nil {
		fmt.Printf("1----")
		if preNode != nil {
			fmt.Printf("preNode:%d|", preNode.Val)
			if firstNode == nil {
				firstNode = preNode
				result = preNode
			} else {
				result.Next = preNode
				result = result.Next
			}
		}
		tmp := head
		tmp2 := &ListNode{Val: tmp.Val}
		value := 0
		for i := 0; i < n; i++ {
			if tmp.Next != nil {
				tmp = tmp.Next
				value++

			} else {
				break
			}
		}
		fmt.Printf("%d", value)
		if value == n-1 {
			fmt.Printf("找到,")
			preNode = nil
			head = head.Next
			continue
		}
		preNode = tmp2
		head = head.Next
	}
	if preNode != nil {
		fmt.Printf("preNode:%d|", preNode.Val)
		if firstNode == nil {
			firstNode = preNode
			result = preNode
		} else {
			result.Next = preNode
			result = result.Next
		}
	}
	return firstNode
}