S2T2

Jim Randell 7:45 am on 13 March 2019 Permalink Reply
Tags: by: Danny Roth ( 84 )   

• 

  Jim Randell 7:47 am on 13 March 2019 Permalink | Reply

  We can use the [[ SubstitutedExpression() ]] solver from the enigma.py library to solve the alphametic expressions directly.

  This run-file executes in 119ms.

  Run: [ @repl.it ]

  #! python3 -m enigma -rr
  
  SubstitutedExpression
  
  --digits="1-9"
  --answer="GREEN"
  
  "RED * GREY = YELLOW"
  "is_square(RED)"  # optional
  

  Solution: GREEN = 21668.

  The [[ is_square(RED) ]] condition is optional (in that there are no further solutions if it is omitted), but it verifies the statement of the problem, and also allows the run-file to execute a little faster (and is convenient when pursuing a manual solution).

  LikeLike

• 

  GeoffR 12:12 pm on 13 March 2019 Permalink | Reply

  % A solution in MinZinc 
  include "globals.mzn";
  
  var 1..9:R; var 1..9:E; var 1..9:D; var 1..9:G; var 1..9:Y; 
  var 1..9:L; var 1..9:O; var 1..9:W; var 1..9:N; 
  
  constraint all_different([R, E, D, G, Y, L, O, W, N]);
  
  var 100..999: RED = 100*R + 10*E + D;
  var 1000..9999: GREY = 1000*G + 100*R + 10*E + Y;
  var 100000..999999: YELLOW = 100000*Y + 10000*E + 1000*L + 100*L + 10*O + W;
  var 10000..99999: GREEN =10000*G + 1000*R + 110*E + N;
  
  set of int: sq3 = {n*n | n in 10..31};
  constraint RED in sq3;
  
  constraint RED * GREY == YELLOW;
  
  solve satisfy;
  
  output [ "GREEN = " ++ show(GREEN)  ++ "\n"
  ++ show(RED) ++ " X " ++ show(GREY) ++ " = " ++ show(YELLOW)];
  
  % GREEN = 21668
  % 169 X 2163 = 365547
  % time elapsed: 0.02 s
  
  
  

  LikeLike