Quoting kata description, "if you have trouble discerning if the particular sequence of 1's is a dot or a dash, assume it's a dot". :)

Dijkstra is good. Use a deque should help in the speed. I got 3XX ms in python.

Only 1 honor score for this kata? I thought 3rd kyu should get me 5 honors...

what if the input is '111000111'?
for unitLen=1, '111' is '-', '000' is letter separator, so the morse code is '- -', so this decodes as 'TT'
for unitLen=3, '111' is '.', '000' is code separator, so the morse is '..', so this decode as 'I'

both look correct to me. Could anyone tell me what in my interpretation is wrong? Many thanks!