% % Hardy's 1729 problem in MiniZinc. % % From Hardy "A Mathematician's Apology" % """ % I had ridden in taxi cab 1729 and remarked that the number seemed to % be rather a dull one. I hoped it was not an unfavorable omen. % "No", he replied, "it is a very integresting number: it is the smallest % number expressed as the sum of two cubes in two different ways. % """ % % Solution: % X1: 1 % X2: 12 % Y1: 9 % Y2: 10 % Z: 1729 % % This MiniZinc model was created by Hakan Kjellerstrand, hakank@bonetmail.com % See also my MiniZinc page: http://www.hakank.org/minizinc % % include "globals.mzn"; var int: X1; var int: X2; var int: Y1; var int: Y2; var int: Z; solve satisfy; % solve minimize Z; constraint X1 > 0 /\ X2 > 0 /\ Y1 > 0 /\ Y2 > 0 /\ Z > 0 /\ X1 <= X2 /\ Y1 <= Y2 % symmetry breaking /\ X1 != Y1 /\ X1 != Y2 /\ X1*X1*X1 + X2*X2*X2 = Z /\ Y1*Y1*Y1 + Y2*Y2*Y2 = Z ; output [ "X1: ", show(X1), "\n", "X2: ", show(X2), "\n", "Y1: ", show(Y1), "\n", "Y2: ", show(Y2), "\n", "Z : ", show(Z), "\n", ];