Source: https://leetcode.com/problems/logger-rate-limiter/

Design a logger system that receives a stream of messages along with their timestamps. Each unique message should only be printed at most every 10 seconds (i.e. a message printed at timestamp t will prevent other identical messages from being printed until timestamp t + 10). All messages will come in chronological order. Several messages may arrive at the same timestamp. Implement the Logger class: Logger() Initializes the logger object. bool shouldPrintMessage(int timestamp, string message) Returns true if the message should be printed in the given timestamp, otherwise returns false.



var Logger = function() {
  // Keep track of message to next valid timestamp map
  this.messageMap = new Map();  
};


/** 
 * @param {number} timestamp 
 * @param {string} message
 * @return {boolean}
 */
// O(1) time, O(N) space
Logger.prototype.shouldPrintMessage = function(timestamp, message) {
  // If the message is not in the map, set the message in the map with the next valid timestamp + 10 and return true
  if (!this.messageMap.has(message)) {
    this.messageMap.set(message, timestamp + 10);
    return true;
  }


  // If the message is in the map and the timestamp is < message's next valid timestamp, return false
  if (timestamp < this.messageMap.get(message)) {
    return false;
  }
  
  // If the message is in the map and the timestamp is >= message's next valid timestamp, set message's next valid timestamp to timestamp + 10 and return true
  this.messageMap.set(message, timestamp + 10);
  return true;
};


/** 
 * Your Logger object will be instantiated and called as such:
 * var obj = new Logger()
 * var param_1 = obj.shouldPrintMessage(timestamp,message)
 */