Add solution #362

Author: JoshCrozier

README.md

@@ -350,6 +350,7 @@
 359|[Logger Rate Limiter](./solutions/0359-logger-rate-limiter.js)|Easy|
 360|[Sort Transformed Array](./solutions/0360-sort-transformed-array.js)|Medium|
 361|[Bomb Enemy](./solutions/0361-bomb-enemy.js)|Medium|
+362|[Design Hit Counter](./solutions/0362-design-hit-counter.js)|Medium|
 363|[Max Sum of Rectangle No Larger Than K](./solutions/0363-max-sum-of-rectangle-no-larger-than-k.js)|Hard|
 365|[Water and Jug Problem](./solutions/0365-water-and-jug-problem.js)|Medium|
 367|[Valid Perfect Square](./solutions/0367-valid-perfect-square.js)|Easy|

solutions/0362-design-hit-counter.js

@@ -0,0 +1,43 @@
+/**
+ * 362. Design Hit Counter
+ * https://leetcode.com/problems/design-hit-counter/
+ * Difficulty: Medium
+ *
+ * Design a hit counter which counts the number of hits received in the past 5 minutes
+ * (i.e., the past 300 seconds).
+ *
+ * Your system should accept a timestamp parameter (in seconds granularity), and you may
+ * assume that calls are being made to the system in chronological order (i.e., timestamp
+ * is monotonically increasing). Several hits may arrive roughly at the same time.
+ *
+ * Implement the HitCounter class:
+ * - HitCounter() Initializes the object of the hit counter system.
+ * - void hit(int timestamp) Records a hit that happened at timestamp (in seconds). Several
+ *   hits may happen at the same timestamp.
+ * - int getHits(int timestamp) Returns the number of hits in the past 5 minutes from timestamp
+ *   (i.e., the past 300 seconds).
+ */
+
+var HitCounter = function() {
+  this.hits = [];
+};
+
+/**
+ * @param {number} timestamp
+ * @return {void}
+ */
+HitCounter.prototype.hit = function(timestamp) {
+  this.hits.push(timestamp);
+};
+
+/**
+ * @param {number} timestamp
+ * @return {number}
+ */
+HitCounter.prototype.getHits = function(timestamp) {
+  const threshold = timestamp - 300;
+  while (this.hits.length && this.hits[0] <= threshold) {
+    this.hits.shift();
+  }
+  return this.hits.length;
+};