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Re: Arithmetic Puzzle (so simple it's hard)

• To: mathgroup at smc.vnet.net
• Subject: [mg71627] Re: Arithmetic Puzzle (so simple it's hard)
• From: croddie at princeton.edu
• Date: Sat, 25 Nov 2006 05:37:08 -0500 (EST)
• References: <200611141006.FAA06684@smc.vnet.net><ejtda3$isg$1@smc.vnet.net>

Janos: get used to functional programming!

Simple program, not too slow; plus you can read and understand it:

doesitwork[partition_] :=
     Module[{b, u, t, a, s, k, f, e},
                {b, u, t, a, s, k, f, e} = partition;
                (100b + 10u +t)(100a + 10s + k) == 10000f + 1000e +
100a + 10s + t];
Timing[Select [Permutations[{0, 1, 2, 4, 5, 6, 7, 9}], doesitwork]]

Output:
{1.578 Second, {{0, 5, 6, 4, 9, 1, 2, 7}, {6, 7, 0, 1, 4, 2, 9, 5}}}


János wrote:

> Any suggestions to make it faster would be highly appreciated.  /It
> took 526 seconds to run with above parameters/
>
> János
> On Nov 14, 2006, at 5:06 AM, Bruce Colletti wrote:
> 
> > How would this problem be solved in Mathematica?

• Follow-Ups:
  • Re: Re: Arithmetic Puzzle (so simple it's hard)
    • From: János <janos.lobb@yale.edu>
  • Re: Re: Arithmetic Puzzle (so simple it's hard)
    • From: Andrzej Kozlowski <akoz@mimuw.edu.pl>

• References:
  • Arithmetic Puzzle (so simple it's hard)
    • From: Bruce Colletti <vze269bv@verizon.net>