I think the idea in parent post is: fill the dictionary (I would use a 200 entries array though), iterate over the keys in sorted order summing the values, stop when you are at N/2. The 'iterate over keys in order' part depends heavily on the data structure choice of the dictionary (good for treemaps, bad for hashmaps, best for preallocated array).

Incidentally this falls in the 'sort an then pick the middle' because the original text says nowhere that is must be a n*log(n) sort and what I described here is essentially the same but with counting sort (and a couple redundant steps removed).