Merge branch 'master' of https://github.com/azl397985856/leetcode

Author: robot

Diff for: problems/146.lru-cache.md

@@ -110,72 +110,85 @@ function put (key, value) {
 JS Code:
 
 ```js
-function ListNode(key, val) {
-  this.key = key;
-  this.val = val;
-  this.pre = this.next = null;
-}
-
-var LRUCache = function (capacity) {
-  this.capacity = capacity;
-  this.size = 0;
-  this.data = {};
-  this.head = new ListNode();
-  this.tail = new ListNode();
-  this.head.next = this.tail;
-  this.tail.pre = this.head;
+class ListNode{
+    constructor(key, val){
+        this.key = key;
+        this.val = val;
+        this.pre = null;
+        this.next = null;
+    }
 };
 
-function get(key) {
-  if (this.data[key] !== undefined) {
-    let node = this.data[key];
-    this.removeNode(node);
-    this.appendHead(node);
-    return node.val;
-  } else {
-    return -1;
-  }
-}
+class LRUCache{
+    constructor(capacity){
+        this.capacity = capacity;
+        this.size = 0;
+        this.data = {};
+        this.head = new ListNode();
+        this.tail = new ListNode();
+        this.head.next = this.tail;
+        this.tail.pre = this.head;
+    }
 
-function put(key, value) {
-  let node;
-  if (this.data[key] !== undefined) {
-    node = this.data[key];
-    this.removeNode(node);
-    node.val = value;
-  } else {
-    node = new ListNode(key, value);
-    this.data[key] = node;
-    if (this.size < this.capacity) {
-      this.size++;
-    } else {
-      key = this.removeTail();
-      delete this.data[key];
+    get(key){
+        if(!this.data[key]) return -1;
+        else{
+            let node = this.data[key];
+            this.removeNode(node);
+            this.appendHead(node);
+            
+            return node.val;
+        }
     }
-  }
-  this.appendHead(node);
-}
 
-function removeNode(node) {
-  let preNode = node.pre,
-    nextNode = node.next;
-  preNode.next = nextNode;
-  nextNode.pre = preNode;
-}
+    put(key, value){
+        if(!this.data[key]){
+            let node = new ListNode(key, value);
 
-function appendHead(node) {
-  let firstNode = this.head.next;
-  this.head.next = node;
-  node.pre = this.head;
-  node.next = firstNode;
-  firstNode.pre = node;
-}
+            this.data[key] = node;
+            this.appendHead(node);
+            this.size++;
+
+            if(this.size > this.capacity){
+                const lastKey = this.removeTail();
+                delete this.data[lastKey];
+                this.size--;
+            }
 
-function removeTail() {
-  let key = this.tail.pre.key;
-  this.removeNode(this.tail.pre);
-  return key;
+        }else{
+            let node = this.data[key];
+            this.removeNode(node);
+            node.val = value;
+            this.appendHead(node);
+        }   
+    }
+
+    removeNode(node){
+        let preNode = node.pre;
+        let nextNode = node.next;
+
+        preNode.next = nextNode;
+        nextNode.pre = preNode;
+    }
+
+    appendHead(node){
+        let firstNode = this.head.next;
+
+        this.head.next = node;
+        node.pre = this.head;
+        node.next = firstNode;
+        firstNode.pre = node;
+    }
+
+    removeTail(){
+        let key = this.tail.pre.key;
+
+        this.removeNode(this.tail.pre);
+        
+        return key;
+    }
 }
+
 ```
 
 Go Code: