I have a very nice example of a challenge very tricky, and a nice test for an AL:
Morse Chaos:
The new radio operator intercepted in his first day at work some morse code, and as he was hearing the short and long beeps he wrote down in a paper a dot or a dash respectively, but he forgot to put spaces to separate letters and words. You know that the text is in English and there are not punctuation marks and your aim is to convert this chaos of dashes and dots into the original text. The signs:
They are in a txt-file: signs.txt.
Note 1: The array of signs is broken in lines to make it easier to copy & paste, but the divisons can be in the middle of a word or even of a letter, so, first of all you should remove the line breaks and have a unique line.
Note 2: All of us know that this challenge can be solved "by hand", try it :-)
Note 3: Worried about what happened to the radio operator? Don't ask if you haven't solved it, you may be the next.
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