Create 1348-tweet-counts-per-frequency.js

Author: everthis

1348-tweet-counts-per-frequency.js

@@ -0,0 +1,54 @@
+const createNode = val => ({ val, left: null, right: null });
+class BinarySearchTree {
+  constructor() {
+    this.root = null;
+  }
+  insert(val, cur = this.root) {
+    const node = createNode(val);
+    if (!this.root) { this.root = node; return; }
+    if (val >= cur.val) {
+      !cur.right ? (cur.right = node) : this.insert(val, cur.right);
+    } else {
+      !cur.left ? (cur.left = node) : this.insert(val, cur.left);
+    }
+  }
+  traversal(low, high, interval, intervals, cur = this.root) {
+    if (!cur) return;
+    if (cur.val <= high && cur.val >= low) {
+      ++intervals[Math.floor((cur.val - low + 1) / interval)];
+    }
+    cur.val > low && this.traversal(low, high, interval, intervals, cur.left);
+    cur.val < high && this.traversal(low, high, interval, intervals, cur.right);
+  }
+};
+class TweetCounts {
+  constructor() {
+    this.freqInterval = {
+      minute: 60,
+      hour: 3600,
+      day: 86400,
+    };
+    this.data = new Map();
+  }
+
+  recordTweet(name, time) {
+    if (this.data.has(name) === false) {
+      this.data.set(name, new BinarySearchTree());
+    }
+    this.data.get(name).insert(time);
+  }
+
+  getTweetCountsPerFrequency(freq, name, start, end) {
+    const interval = this.freqInterval[freq];
+    const ret = new Array(Math.ceil((end - start + 1) / interval)).fill(0);
+    this.data.has(name) && this.data.get(name).traversal(start, end, interval, ret);
+    return ret;
+  }
+};
+
+/** 
+ * Your TweetCounts object will be instantiated and called as such:
+ * var obj = new TweetCounts()
+ * obj.recordTweet(tweetName,time)
+ * var param_2 = obj.getTweetCountsPerFrequency(freq,tweetName,startTime,endTime)
+ */