1797. 设计一个验证系统

Author: w2xi

README.md

@@ -202,6 +202,7 @@
 |1664|[生成平衡数组的方案数](https://leetcode.cn/problems/ways-to-make-a-fair-array/)|[JavaScript](./algorithms/ways-to-make-a-fair-array.js)|Medium|
 |1669|[合并两个链表](https://leetcode.cn/problems/merge-in-between-linked-lists/)|[JavaScript](./algorithms/merge-in-between-linked-lists.js)|Medium|
 |1780|[判断一个数字是否可以表示成三的幂的和](https://leetcode.cn/problems/check-if-number-is-a-sum-of-powers-of-three/)|[JavaScript](./algorithms/check-if-number-is-a-sum-of-powers-of-three.js)|Medium|
+|1797|[设计一个验证系统](https://leetcode.cn/problems/design-authentication-manager/)|[JavaScript](./algorithms/design-authentication-manager.js)|Medium|
 |1807|[替换字符串中的括号内容](https://leetcode.cn/problems/evaluate-the-bracket-pairs-of-a-string/)|[JavaScript](./algorithms/evaluate-the-bracket-pairs-of-a-string.js)|Medium|
 |1813|[句子相似性 III](https://leetcode.cn/problems/sentence-similarity-iii/)|[JavaScript](./algorithms/sentence-similarity-iii.js)|Medium|
 |1814|[统计一个数组中好对子的数目](https://leetcode.cn/problems/count-nice-pairs-in-an-array/)|[JavaScript](./algorithms/count-nice-pairs-in-an-array.js)|Medium|

algorithms/design-authentication-manager.js

@@ -0,0 +1,53 @@
+/**
+ * @param {number} timeToLive
+ */
+var AuthenticationManager = function(timeToLive) {
+  this.timeToLive = timeToLive;
+  this.map = new Map(); // tokenId -> liveTime (latest)
+};
+
+/** 
+ * @param {string} tokenId 
+ * @param {number} currentTime
+ * @return {void}
+ */
+AuthenticationManager.prototype.generate = function(tokenId, currentTime) {
+  this.map.set(tokenId, currentTime + this.timeToLive);
+};
+
+/** 
+ * @param {string} tokenId 
+ * @param {number} currentTime
+ * @return {void}
+ */
+AuthenticationManager.prototype.renew = function(tokenId, currentTime) {
+  const liveTime = this.map.get(tokenId);
+  if (this.map.has(tokenId) && liveTime > currentTime) {
+    this.map.set(tokenId, currentTime + this.timeToLive);
+  }
+};
+
+/** 
+ * @param {number} currentTime
+ * @return {number}
+ */
+AuthenticationManager.prototype.countUnexpiredTokens = function(currentTime) {
+  let count = 0;
+  this.map.forEach((item) => {
+    if (item > currentTime) {
+      count++;
+    } else {
+      this.map.delete(key); // 移除过期的 token
+    }
+  });
+  return count;
+};
+
+
+/**
+ * Your AuthenticationManager object will be instantiated and called as such:
+ * var obj = new AuthenticationManager(timeToLive)
+ * obj.generate(tokenId,currentTime)
+ * obj.renew(tokenId,currentTime)
+ * var param_3 = obj.countUnexpiredTokens(currentTime)
+ */