0933-number-of-recent-calls.js

/**
 * 933. Number of Recent Calls
 * https://leetcode.com/problems/number-of-recent-calls/
 * Difficulty: Easy
 *
 * You have a RecentCounter class which counts the number of recent requests within
 * a certain time frame.
 *
 * Implement the RecentCounter class:
 * - RecentCounter() Initializes the counter with zero recent requests.
 * - int ping(int t) Adds a new request at time t, where t represents some time in
 *   milliseconds, and returns the number of requests that has happened in the past
 *   3000 milliseconds (including the new request). Specifically, return the number
 *   of requests that have happened in the inclusive range [t - 3000, t].
 *
 * It is guaranteed that every call to ping uses a strictly larger value of t than
 * the previous call.
 */


var RecentCounter = function() {
  this.queue = [];
};

/**
 * @param {number} t
 * @return {number}
 */
RecentCounter.prototype.ping = function(t) {
  this.queue.push(t);
  while (this.queue[0] < t - 3000) {
    this.queue.shift();
  }
  return this.queue.length;
};