title: Which one is faster? List.contains() or Map.containsKey()
body: <p>I'm writing an algorithm where I look for pairs of values which when added together results in another value I'm looking for.</p>
  
  <p>I figured out that using a <code>Map</code> will speed up my algorithm from O(n²). I later realized that I don't really use the values contained in my <code>Map</code> so a <code>List</code> will suffice.</p>
  
  <p>I did a power search on Google but I did not find any information on the asymptotic running time of those methods in the title of my question.</p>
  
  <p>Can you point out where should I look for such information?</p>