title: comparing objects in NSSet with objects in NSArray
body: <p>I've been pondering over this problem for a while now but I am not able to get a nice concise efficient solution yet.</p>
  
  <p>Problem:</p>
  
  <p>I have a recipe list which is an NSArray, every recipe object contains ingredients as NSSet objects. Data is one to many relationship &amp; is coming from coredata. 
  Now there is another list an NSArray which contains items(ingredients) a particular person currently have.</p>
  
  <p>Now I have to somehow compare currently present items which user have with ingredients in recipes &amp; recommend user recipes in a table view with sections like all items present, 1 item missing, two items missing and three items missing.</p>
  
  <p>How do you guys think I should approach this problem. 
  I have tried a few things but I end up getting even more lost each time.</p>
  
  <p>Any help/pointers will be highly appreciated </p>