title: Amazon Interview- Design Meeting Scheduler
body: <p>Lately, I took an interview. I was asked to design a meeting scheduler, just like in the Microsoft outlook calendar or the gmail calendar. 
  I proposed that I will create an array of 48 for each day. Every 30 min representing the array entry. </p>
  
  <p>I have to make sure that the next appointment does not collide with a previous meeting.</p>
  
  <p>My solution works fine but it wastes too much memory. </p>
  
  <p>Can anyone please tell me how do I find a better solution to detect collision for meetings. </p>
  
  <p>I don't know all the meetings at the beginning. They will be added randomly later. </p>
  
  <p>Thanks, </p>