Comments on: Euler Problem 120 http://www.dailydoseofexcel.com/archives/2009/06/06/euler-problem-120/ Daily posts of Excel tips…and other stuff Thu, 09 Feb 2012 19:28:40 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Michael http://www.dailydoseofexcel.com/archives/2009/06/06/euler-problem-120/#comment-39750 Michael Tue, 09 Jun 2009 14:48:00 +0000 http://www.dailydoseofexcel.com/?p=2538#comment-39750 <p>Hi fzz -</p> <p>Thanks. Yep, the 5 lines from n = 2 to n = n - 1 can be replaced with the single line </p> <p>n = (a - 1)2</p> <p>which makes the simple code even simpler ;-)</p> <p>I didn't adequately express my thoughts above: 2x it should be "This <i>pattern</i> is true for all..."</p> <p>...mrt</p> Hi fzz -

Thanks. Yep, the 5 lines from n = 2 to n = n – 1 can be replaced with the single line

n = (a – 1)2

which makes the simple code even simpler ;-)

I didn’t adequately express my thoughts above: 2x it should be “This pattern is true for all…”

…mrt

]]> By: fzz http://www.dailydoseofexcel.com/archives/2009/06/06/euler-problem-120/#comment-39744 fzz Tue, 09 Jun 2009 09:00:00 +0000 http://www.dailydoseofexcel.com/?p=2538#comment-39744 <p>This is one Euler problen that could be solved with a single worksheet formula. Your inner While...Wend loop is unnecessary. You're finding the largest even number strictly less than a. That doesn't require a loop. For odd a, it's a-1, and for even a it's a-2. Both can be combined into a - 2 + (a Mod 2). Or as a worksheet formula,</p> <p>=SUMPRODUCT(ROW(3:1000)*(ROW(3:1000)-2+MOD(ROW(3:1000),2)))</p> This is one Euler problen that could be solved with a single worksheet formula. Your inner While…Wend loop is unnecessary. You’re finding the largest even number strictly less than a. That doesn’t require a loop. For odd a, it’s a-1, and for even a it’s a-2. Both can be combined into a – 2 + (a Mod 2). Or as a worksheet formula,

=SUMPRODUCT(ROW(3:1000)*(ROW(3:1000)-2+MOD(ROW(3:1000),2)))

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