> What dictionary? How do you generate it (handwaving notwithstanding, as mentioned)? It all comes back down to encoding, rather than aggregation of letter coun

> What dictionary? How do you generate it (handwaving notwithstanding, as mentioned)? It all comes back down to encoding, rather than aggregation of letter count.^ OK, first, I'm not sure your original post presents the right reading of the blog post. Sorting and using a dictionary are given in the blog post as two separate solutions, not two components of one solution. (Sorry if I'm mistaken – but it seems to read this way to me?) Regarding your concerns about dictionary generation: I might be missing something, but this doesn't seem so hard? The first thought that comes to mind is to associate to each word a 26-tuple of integers that counts the number of appearances of each letter of the alphabet. This can be done in O(N) time, since it's an O(1) operation for each word (length of words is assumed to be bounded above by some constant). Then 1) Create a (multi)-dictionary with these tuples as keys. Insert is O(1) in the average case, you're doing it N times, so this step is O(N). 2) Go through the dictionary by key and delete all singletons. Again O(N). 3) Print the dictionary by key to get the groups of anagrams. This is O(N) on average. It's not immediately clear to me whether one can do O(N) in the worst case – are you claiming that your way does that? [Of course, this is not so far off from what you're doing. But it illustrates the claim that bit arrays are not necessary.]