Artifact 329a03d219b36e695a0615f6d5bc239f4bc0f052

File master_theorem/murder_at_sea.rx part of check-in [48a095494d] - more master theorem solutions by crc on 2011-09-05 15:12:40. [annotate]

Flag semaphores are at the heart of this puzzle. In the text,
M provides a series of times. These correspond to flag semaphore
positions. If you picture the flag positions as the hands on an
analog clock, this should become clear.

So:

  715 130 625 730 925 745 730 915 700

These are our times.

  : display ( n- )
    [ 730 = ] [ drop 'A putc ] when
    [ 130 = ] [ drop 'E putc ] when
    [ 625 = ] [ drop 'G putc ] when
    [ 745 = ] [ drop 'H putc ] when
    [ 700 = ] [ drop 'K putc ] when
    [ 715 = ] [ drop 'M putc ] when
    [ 915 = ] [ drop 'R putc ] when
    [ 925 = ] [ drop 'S putc ] when ;

Less elegant than a lookup table, but suitable for this
quick and dirty solution. Map each time to a character
and display them.

  "" ^buffer'set

Setup a temporary string as a buffer.

  depth [ ^buffer'add ] times

Adds all of the times to the buffer.

  ^buffer'start ^strings'reverse

Reverse the order of the buffer, and leave a pointer...

  [ @ display ] ^types'STRING each@

And apply a quote to each item in the buffer. This is pretty
simple: fetch the item, and give it to the display function.

This yields the answer: MEGASHARK

All in all, a boring puzzle. Once you figure out that M wants
you to use flag semaphores in place of times, it's easy to find
the answer.