From 22f88789b5dd579d7e6eb6bb362b6d2c26dea990 Mon Sep 17 00:00:00 2001
From: dreamapple <2451731631@qq.com>
Date: Tue, 4 Dec 2018 17:12:03 +0800
Subject: [PATCH] =?UTF-8?q?1.=E6=B7=BB=E5=8A=A0JavaScript=E7=89=88?=
 =?UTF-8?q?=E6=9C=AC=E7=9A=84SkipList=E7=9A=84=E5=AE=9E=E7=8E=B0=202.?=
 =?UTF-8?q?=E4=BF=AE=E6=94=B9JavaScript=E7=89=88=E6=9C=AChashmap=E6=96=87?=
 =?UTF-8?q?=E4=BB=B6=E7=9A=84=E5=BA=8F=E5=8F=B7?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .gitignore                                    |  3 +
 javascript/17_skiplist/SkipList.js            | 95 +++++++++++++++++++
 .../{17_hashmap => 18_hashmap}/HashTable.html |  0
 3 files changed, 98 insertions(+)
 create mode 100644 javascript/17_skiplist/SkipList.js
 rename javascript/{17_hashmap => 18_hashmap}/HashTable.html (100%)

diff --git a/.gitignore b/.gitignore
index c456446b..fb159b51 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,3 +25,6 @@ hs_err_pid*
 # editor files
 .vscode
 .*.swp
+
+# WebStorm
+.idea/
diff --git a/javascript/17_skiplist/SkipList.js b/javascript/17_skiplist/SkipList.js
new file mode 100644
index 00000000..e123f71f
--- /dev/null
+++ b/javascript/17_skiplist/SkipList.js
@@ -0,0 +1,95 @@
+/**
+ * author dreamapplehappy
+ * 关于代码的一些解释可以看一下这里：https://github.com/dreamapplehappy/blog/tree/master/2018/12/02
+ */
+
+const MAX_LEVEL = 16;
+
+class Node{
+    data = -1;
+    maxLevel = 0;
+    refer = new Array(MAX_LEVEL);
+}
+
+class SkipList{
+    levelCount = 1;
+    head = new Node();
+
+    static randomLevel() {
+        let level = 1;
+        for(let i = 1; i < MAX_LEVEL; i++) {
+            if(Math.random() < 0.5) {
+                level++;
+            }
+        }
+        return level;
+    }
+
+    insert(value) {
+        const level = SkipList.randomLevel();
+        const newNode = new Node();
+        newNode.data = value;
+        newNode.maxLevel = level;
+        const update = new Array(level).fill(new Node());
+        let p = this.head;
+        for(let i = level - 1; i >= 0; i--) {
+            while(p.refer[i] !== undefined && p.refer[i].data < value) {
+                p = p.refer[i];
+            }
+            update[i] = p;
+        }
+        for(let i = 0; i < level; i++) {
+            newNode.refer[i] = update[i].refer[i];
+            update[i].refer[i] = newNode;
+        }
+        if(this.levelCount < level) {
+            this.levelCount = level;
+        }
+    }
+
+    find(value) {
+        if(!value){return null}
+        let p = this.head;
+        for(let i = this.levelCount - 1; i >= 0; i--) {
+            while(p.refer[i] !== undefined && p.refer[i].data < value) {
+                p = p.refer[i];
+            }
+        }
+
+        if(p.refer[0] !== undefined && p.refer[0].data === value) {
+            return p.refer[0];
+        }
+        return null;
+    }
+
+    remove(value) {
+        let _node;
+        let p = this.head;
+        const update = new Array(new Node());
+        for(let i = this.levelCount - 1; i >= 0; i--) {
+            while(p.refer[i] !== undefined && p.refer[i].data < value){
+                p = p.refer[i];
+            }
+            update[i] = p;
+        }
+
+        if(p.refer[0] !== undefined && p.refer[0].data === value) {
+            _node = p.refer[0];
+            for(let i = 0; i <= this.levelCount - 1; i++) {
+                if(update[i].refer[i] !== undefined && update[i].refer[i].data === value) {
+                    update[i].refer[i] = update[i].refer[i].refer[i];
+                }
+            }
+            return _node;
+        }
+        return null;
+    }
+
+    printAll() {
+        let p = this.head;
+        while(p.refer[0] !== undefined) {
+            // console.log(p.refer[0].data)
+            p = p.refer[0];
+        }
+    }
+}
diff --git a/javascript/17_hashmap/HashTable.html b/javascript/18_hashmap/HashTable.html
similarity index 100%
rename from javascript/17_hashmap/HashTable.html
rename to javascript/18_hashmap/HashTable.html