写一段go实现跳表的代码

### 回答1：

package mainimport (
"fmt"
)// 节点
type node struct {
key int
value string
left *node
right *node
}// 跳表
type skipList struct {
head *node
length int
}func main() { sl := &skipList{
head: &node{
key: 0,
value: "",
left: nil,
right: nil,
},
length: 0,
} // 插入
sl.insert(1, "a")
sl.insert(2, "b")
sl.insert(3, "c")
sl.insert(4, "d")
sl.insert(5, "e")
fmt.Println(sl) // 查找
fmt.Println(sl.find(4)) // 删除
sl.delete(4)
fmt.Println(sl)
}// 插入
func (sl *skipList) insert(key int, value string) {
// 创建新节点
newNode := &node{
key: key,
value: value,
left: nil,
right: nil,
} // 定义当前节点为头结点
cur := sl.head // 寻找位置插入
for cur.right != nil {
if cur.right.key > key {
break
}
cur = cur.right
} // 插入
newNode.right = cur.right
cur.right = newNode
newNode.left = cur // 增加长度
sl.length++
}// 查找
func (sl *skipList) find(key int) string {
cur := sl.head for cur.right != nil {
if cur.right.key > key {
break
}
cur = cur.right
} if cur.key == key {
return cur.value
} return ""
}// 删除
func (sl *skipList) delete(key int) {
cur := sl.head for cur.right != nil {
if cur.right.key > key {
break
}
cur = cur.right
} if cur.right != nil && cur.right.key == key {
cur.right = cur.right.right
if cur.right != nil {
cur.right.left = cur
}
sl.length--
}
}

### 回答2：
跳表是一种快速查找的数据结构，类似于有序链表加上多级索引的结构。下面是用Go语言实现跳表的代码：

package main

import (
	"fmt"
	"math"
)

type SkipListNode struct {
	value int
	next  []*SkipListNode
}

type SkipList struct {
	head   *SkipListNode
	level  int
	length int
}

func NewSkipListNode(value, level int) *SkipListNode {
	return &SkipListNode{
		value: value,
		next:  make([]*SkipListNode, level),
	}
}

func NewSkipList() *SkipList {
	// 创建头节点，值为负无穷
	head := NewSkipListNode(math.MinInt32, 32)

	return &SkipList{
		head:   head,
		level:  0,
		length: 0,
	}
}

func (list *SkipList) Insert(value int) {
	update := make([]*SkipListNode, list.level+1)
	node := list.head

	// 查找插入位置
	for i := list.level; i >= 0; i-- {
		for node.next[i] != nil && node.next[i].value < value {
			node = node.next[i]
		}
		update[i] = node
	}

	// 随机生成索引层数，使其符合跳表的概率分布
	level := 0
	for (level < 32-1) && (level < list.level+1) && (rand.Int()%2 == 0) {
		level++
	}

	// 创建新节点
	insertNode := NewSkipListNode(value, level+1)

	// 更新索引
	for i := 0; i <= level; i++ {
		insertNode.next[i] = update[i].next[i]
		update[i].next[i] = insertNode
	}

	// 更新跳表的层数
	if level > list.level {
		list.level = level
	}

	list.length++
}

func (list *SkipList) Search(target int) bool {
	node := list.head

	// 从最高层开始搜索
	for i := list.level; i >= 0; i-- {
		for node.next[i] != nil && node.next[i].value <= target {
			if node.next[i].value == target {
				return true
			}
			node = node.next[i]
		}
	}

	return false
}

func main() {
	list := NewSkipList()

	list.Insert(3)
	list.Insert(5)
	list.Insert(8)
	list.Insert(10)
	list.Insert(12)

	fmt.Println(list.Search(8))  // true
	fmt.Println(list.Search(6))  // false
}

以上是一个简单的跳表实现，包括插入和搜索两个基本操作。通过随机生成索引层数，可以实现快速的查找。

### 回答3：
下面是使用Go语言实现跳表的代码段示例：

package main

import (
	"fmt"
	"math"
	"math/rand"
)

type Node struct {
	value int
	next  []*Node
}

type SkipList struct {
	head  *Node
	level int
}

func newNode(value, level int) *Node {
	return &Node{
		value: value,
		next:  make([]*Node, level),
	}
}

func newSkipList() *SkipList {
	return &SkipList{
		head:  newNode(math.MinInt32, 1),
		level: 1,
	}
}

func (skiplist *SkipList) search(target int) bool {
	curr := skiplist.head
	for i := skiplist.level - 1; i >= 0; i-- {
		for curr.next[i] != nil && curr.next[i].value < target {
			curr = curr.next[i]
		}
		if curr.next[i] != nil && curr.next[i].value == target {
			return true
		}
	}
	return false
}

func (skiplist *SkipList) insert(value int) {
	level := skiplist.randomLevel()
	newNode := newNode(value, level)

	update := make([]*Node, level)
	curr := skiplist.head
	for i := level - 1; i >= 0; i-- {
		for curr.next[i] != nil && curr.next[i].value < value {
			curr = curr.next[i]
		}
		update[i] = curr
	}

	for i := 0; i < level; i++ {
		newNode.next[i] = update[i].next[i]
		update[i].next[i] = newNode
	}

	if level > skiplist.level {
		skiplist.level = level
	}
}

func (skiplist *SkipList) erase(value int) {
	update := make([]*Node, skiplist.level)
	curr := skiplist.head
	for i := skiplist.level - 1; i >= 0; i-- {
		for curr.next[i] != nil && curr.next[i].value < value {
			curr = curr.next[i]
		}
		update[i] = curr
	}

	if curr.next[0] != nil && curr.next[0].value == value {
		for i := skiplist.level - 1; i >= 0; i-- {
			if update[i].next[i] != nil && update[i].next[i].value == value {
				update[i].next[i] = update[i].next[i].next[i]
			}
		}
	}
}

func (skiplist *SkipList) randomLevel() int {
	level := 1
	for rand.Float32() < 0.5 && level < 32 {
		level++
	}
	return level
}

func main() {
	skiplist := newSkipList()

	skiplist.insert(3)
	skiplist.insert(6)
	skiplist.insert(9)
	skiplist.insert(2)
	skiplist.insert(5)
	skiplist.insert(8)

	fmt.Println(skiplist.search(6)) // 输出: true
	fmt.Println(skiplist.search(12)) // 输出: false

	skiplist.erase(6)

	fmt.Println(skiplist.search(6)) // 输出: false
}

此代码段实现了一个基本的跳表数据结构，其中SkipList是一个包含了跳表头结点和层数的结构体。可以通过insert方法向跳表中插入元素，通过search方法在跳表中搜索元素，通过erase方法删除跳表中的某个元素。运行main函数可以看到跳表的基本操作结果。