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N-queens benchmark and the HP-17BII
Posted by Thomas Klemm on 7 Feb 2011, 5:48 a.m.
QUEENS: Q=A+B+C+D+E+F+G+H+ (I:1:8:1: (J:1:8:1: IF(I<>J AND SQ(I-J)<>1: (K:1:8:1: IF(I<>K AND SQ(I-K)<>4 AND J<>K AND SQ(J-K)<>1: (L:1:8:1: IF(I<>L AND SQ(I-L)<>9 AND J<>L AND SQ(J-L)<>4 AND K<>L AND SQ(K-L)<>1: (M:1:8:1: IF(I<>M AND SQ(I-M)<>16 AND J<>M AND SQ(J-M)<>9 AND K<>M AND SQ(K-M)<>4 AND L<>M AND SQ(L-M)<>1: (N:1:8:1: IF(I<>N AND SQ(I-N)<>25 AND J<>N AND SQ(J-N)<>16 AND K<>N AND SQ(K-N)<>9 AND L<>N AND SQ(L-N)<>4 AND M<>N AND SQ(M-N)<>1: (O:1:8:1: IF(I<>O AND SQ(I-O)<>36 AND J<>O AND SQ(J-O)<>25 AND K<>O AND SQ(K-O)<>16 AND L<>O AND SQ(L-O)<>9 AND M<>O AND SQ(M-O)<>4 AND N<>O AND SQ(N-O)<>1: (P:1:8:1: IF(I<>P AND SQ(I-P)<>49 AND J<>P AND SQ(J-P)<>36 AND K<>P AND SQ(K-P)<>25 AND L<>P AND SQ(L-P)<>16 AND M<>P AND SQ(M-P)<>9 AND N<>P AND SQ(N-P)<>4 AND O<>P AND SQ(O-P)<>1: L(A:I)xL(B:J)xL(C:K)xL(D:L)xL(E:M)xL(F:N)xL(G:O)xL(H:P)/0 :0)):0)):0)):0)):0)):0)):0)))
Solve the equation for Q. After a while (3:29) you get an error message:
SOLUTION NOT FOUND
Now you can recall the solution in the variables A-H. The result { 1, 5, 8, 6, 3, 7, 2, 4 } corresponds to the following configuration:
A B C D E F G H +---+---+---+---+---+---+---+---+ 8 | | | # | | | | | | +---+---+---+---+---+---+---+---+ 7 | | | | | | # | | | +---+---+---+---+---+---+---+---+ 6 | | | | # | | | | | +---+---+---+---+---+---+---+---+ 5 | | # | | | | | | | +---+---+---+---+---+---+---+---+ 4 | | | | | | | | # | +---+---+---+---+---+---+---+---+ 3 | | | | | # | | | | +---+---+---+---+---+---+---+---+ 2 | | | | | | | # | | +---+---+---+---+---+---+---+---+ 1 | # | | | | | | | | +---+---+---+---+---+---+---+---+
Calculator Speed Benchmark using the N-Queens Problem
Edited: 7 Feb 2011, 6:27 a.m.