From a2ddea136570c641af17395f43f07e0cc61d5bdc Mon Sep 17 00:00:00 2001 From: kingecg Date: Mon, 24 Feb 2025 00:41:59 +0800 Subject: [PATCH] =?UTF-8?q?=E5=88=A0=E9=99=A4=20skiptable.go?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- skiptable.go | 133 --------------------------------------------------- 1 file changed, 133 deletions(-) delete mode 100644 skiptable.go diff --git a/skiptable.go b/skiptable.go deleted file mode 100644 index b6f6d3d..0000000 --- a/skiptable.go +++ /dev/null @@ -1,133 +0,0 @@ -package main - -import ( - "fmt" - "math/rand" - "time" - ) - - const ( - maxLevel = 32 // 最大层数 - probability = 0.5 // 层数生成概率因子 - ) - - // SkipNode 跳表节点结构 - type SkipNode struct { - key int - value interface{} - forward []*SkipNode // 各层的前进指针 - } - - // NewSkipNode 创建新节点 - func NewSkipNode(key int, value interface{}, level int) *SkipNode { - return &SkipNode{ - key: key, - value: value, - forward: make([]*SkipNode, level), - } - } - - // SkipList 跳表结构 - type SkipList struct { - header *SkipNode // 头节点 - level int // 当前最大层数 - randSrc rand.Source // 随机数源 - } - - // NewSkipList 初始化跳表 - func NewSkipList() *SkipList { - return &SkipList{ - header: NewSkipNode(0, nil, maxLevel), - level: 1, - randSrc: rand.NewSource(time.Now().UnixNano()), - } - } - - // randomLevel 生成随机层数 (抛硬币法) - func (sl *SkipList) randomLevel() int { - level := 1 - for ; level < maxLevel && sl.randSrc.Int63()&0xFFFF < int64(probability*0xFFFF); level++ { - } - return level - } - - // Search 查找键对应的值 - func (sl *SkipList) Search(key int) (interface{}, bool) { - current := sl.header - // 从最高层开始查找 - for i := sl.level - 1; i >= 0; i-- { - // 在当前层向右移动，直到找到大于等于key的节点 - for current.forward[i] != nil && current.forward[i].key < key { - current = current.forward[i] - } - } - // 移动到最底层(0层)的下一个节点 - current = current.forward[0] - if current != nil && current.key == key { - return current.value, true - } - return nil, false - } - - // Insert 插入键值对 - func (sl *SkipList) Insert(key int, value interface{}) { - update := make([]*SkipNode, maxLevel) // 各层需要更新的前驱节点 - current := sl.header - - // 1. 查找各层的前驱节点 - for i := sl.level - 1; i >= 0; i-- { - for current.forward[i] != nil && current.forward[i].key < key { - current = current.forward[i] - } - update[i] = current - } - - // 2. 检查是否已存在相同key - current = current.forward[0] - if current != nil && current.key == key { - current.value = value // 更新值 - return - } - - // 3. 生成新节点的随机层数 - newLevel := sl.randomLevel() - if newLevel > sl.level { - // 补充高层的前驱节点为header - for i := sl.level; i < newLevel; i++ { - update[i] = sl.header - } - sl.level = newLevel - } - - // 4. 创建新节点并插入各层 - newNode := NewSkipNode(key, value, newLevel) - for i := 0; i < newLevel; i++ { - newNode.forward[i] = update[i].forward[i] - update[i].forward[i] = newNode - } - } - - // Delete 删除指定键的节点 - func (sl *SkipList) Delete(key int) bool { - update := make([]*SkipNode, maxLevel) - current := sl.header - - // 1. 查找各层的前驱节点 - for i := sl.level - 1; i >= 0; i-- { - for current.forward[i] != nil && current.forward[i].key < key { - current = current.forward[i] - } - update[i] = current - } - - // 2. 定位到目标节点 - current = current.forward[0] - if current == nil || current.key != key { - return false // 未找到 - } - - // 3. 从各层链表中移除 - for i := 0; i < sl.level; i++ { - if update[i].forward[i] != current { - break // 上层已 -   \ No newline at end of file