S2T2

Jim Randell 8:39 am on 6 February 2026 Permalink Reply
Tags: by: Angela Newing ( 38 )   

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  Jim Randell 8:41 am on 6 February 2026 Permalink | Reply

  Here is a solution using the [[ SubstitutedExpression ]] solver from the enigma.py library.

  The following run file executes in 79ms. (Internal runtime of the generated code is 87µs).

  #! python3 -m enigma -rr
  
  SubstitutedExpression
  
  # we assign queue positions 1 (= front) to 6 (= back)
  --digits="1-6"
  --macro="@Terry = A"
  --macro="@Tony = B"
  --macro="@Tilly = C"
  --macro="@Tommy = D"
  --macro="@Timmy = E"
  --macro="@Trudy = F"
  --macro="@Te = G"  # Tea
  --macro="@HC = H"  # Hot Chocolate
  --macro="@SW = I"  # Sparkling Water
  --macro="@Mk = J"  # Milk
  --macro="@WC = K"  # White Coffee
  --macro="@BC = L"  # Black Coffee
  --distinct="ABCDEF,GHIJKL"
  
  # "Terry was directly behind Hot Chocolate"
  "@HC + 1 = @Terry"
  
  # "Tony (who is not at the front of the queue) ..."
  "@Tony > 1"
  # "... was immediately in front of Sparkling Water ..."
  "@SW - 1 = @Tony"
  # "... (who was not Terry)"
  "@SW != @Terry"
  
  # "Milk was 3 places in front of White Coffee"
  "@WC - 3 = @Mk"
  
  # "Tilly was directly behind Tommy"
  "@Tommy + 1 = @Tilly"
  
  # "Timmy was 2 places ahead of Hot Chocolate"
  "@HC - 2 = @Timmy"
  
  # "The person at the front of the queue had Black Coffee"
  "@BC = 1"
  
  --template="(A B C D E F) (G H I J K L)"
  --solution=""
  --verbose="1-W"
  

  And here is a Python program that runs the solver, and then formats the output nicely:

  from enigma import (SubstitutedExpression, irange, printf)
  
  # load the puzzle
  p = SubstitutedExpression.from_file(["{dir}/teaser2459.run"])
  
  # link names and drinks to symbols
  names = dict(A='Terry', B='Tony', C='Tilly', D='Tommy', E='Timmy', F='Trudy')
  drinks = dict(G='tea', H='hot chocolate', I='sparkling water', J='milk', K='white coffee', L='black coffee')
  
  # solve the puzzle and format solutions
  for s in p.solve(verbose=0):
    # for each position 1-6 fill out a corresponding name and drink
    name = dict((s[k], v) for (k, v) in names.items())
    drink = dict((s[k], v) for (k, v) in drinks.items())
    # output the queue
    for pos in irange(1, 6):
      printf("{pos}: {n}, {d}", n=name.get(pos, '???'), d=drink.get(pos, '???'))
    printf()
  

  Solution: Terry had tea. Trudy was 6th in the queue.

  The positions in the queue and drinks required are:

  1: Timmy, black coffee
  2: Tommy, milk
  3: Tilly, hot chocolate
  4: Terry, tea
  5: Tony, white coffee
  6: Trudy, sparkling water

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