title: Big O Notation for the permutations of a list of words
body: <p>What would be the big O notation of the length of the list of permutations of the characters of a list of words of lenght n?</p>
  
  <p>I just do not know how to express that because it would be like n! for each word where n is the characters of that word but O(n!) is just the complexity of a single word, not a list of n words.</p>
  
  <p>Also, every word may have different sizes.</p>
  
  <p>An example:</p>
  
  <p>Let's say that I have the words "abc", "abcd" and "abcde". If I have to create the permutations of each word, I would end up with a list of lists of strings with lengths of 6, 24 and 120 i.e. the permutations of "abc" will be in the first list, the permutations of the second word will be in the second and so on and so on.</p>
  
  <p>If I use an permutation iterator, how much time will it take to generate all those lists?</p>