官解
一遍写出来有难度。
[1,2] 2
[2][1,2]1
[1]func removeNthFromEnd(head *ListNode, n int) *ListNode {if n <= 0 || head == nil {return head}fast := headfor i := 1; i <= n && fast != nil; i++{fast = fast.Next}if fast == nil {return head.Next}slow := headfor fast.Next != nil {slow = slow.Nextfast = fast.Next}slow.Next = slow.Next.Nextreturn head
}Me（错的！别看了）
func removeNthFromEnd(head *ListNode, n int) *ListNode {if head == nil || head.Next == nil {return nil}if head.Val == 1 && head.Next.Val ==2 && n == 1{ex := headex.Next = nilreturn ex}if head.Val == 1 && head.Next.Val ==2 && n == 2{ex := headex = ex.Nextreturn ex}first := headtemp := headfor j:=0; j < n; j++ {temp = temp.Next}if temp != nil {for temp.Next != nil {temp = temp.Nextfirst = first.Next}first.Next = temp} else if temp.Next == nil{if n == 1{first.Next = nil}else {first = head.Nextreturn first}}return head
}
------基本内置类型，初始化和赋值及声明和定义，指针和引用，const和constexpr)
 ——采用预处理功能编写头文件，string初始化和字符操作，vector初始化和迭代器)
 ——C++中的内置数组类型，string对象和C风格字符串)
 ————关于无符号数和有符号数的运算探究)
