Create LeetCode_362_Hit_Counter_1.ts

anxious-coder-lhs · web-flow · commit 3fc70a228285 · 2020-10-07T09:15:54.000+05:30
diff --git a/level_medium/LeetCode_362_Hit_Counter_1.ts b/level_medium/LeetCode_362_Hit_Counter_1.ts
@@ -0,0 +1,55 @@
+type Hit = {
+    timestamp: number
+    hits: number
+}
+
+/**
+* Problem: Designing a hit counter which counts the total number of hits in the last 5 minutes.
+* Solution: Uses a queue to keep on appending the value of the hits at each request. We do this by using a queue. If the queue contains a value for the same timestamp,
+* we simply update it. If it does not contain, we increment it. While getting the values, we need to add all the values that are within 5 minutes of interval for counting
+* the results. Also, we need to trim all the values that were called before 5 minutes.
+*/
+class HitCounter {
+    
+    hits: Hit[]
+    
+    constructor() {
+        this.hits = []
+    }
+
+    hit(timestamp: number): void {
+        const last = this.hits.length > 0 ? this.hits[this.hits.length - 1] : undefined
+        if (last && last.timestamp === timestamp) {
+            last.hits++
+        } else {
+            this.hits.push({
+                timestamp,
+                hits: 1
+            });
+        }
+    }
+
+    getHits(timestamp: number): number {
+        let pos = this.hits.length - 1
+        let hitItem = this.hits[pos]
+        let total = 0
+        while(hitItem !== undefined && timestamp - hitItem.timestamp < 300) {
+            total += hitItem.hits;
+            pos--
+            hitItem = this.hits[pos]
+        }
+        
+        if (pos > 0) {
+            this.hits = this.hits.slice(pos + 1)
+        }
+        
+        return total;
+    }
+}
+
+/**
+ * Your HitCounter object will be instantiated and called as such:
+ * var obj = new HitCounter()
+ * obj.hit(timestamp)
+ * var param_2 = obj.getHits(timestamp)
+ */
