Comments on: Euler Problem 19 http://www.dailydoseofexcel.com/archives/2008/12/30/euler-problem-19/ Daily posts of Excel tips…and other stuff Wed, 08 Feb 2012 23:58:05 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Hans Schraven http://www.dailydoseofexcel.com/archives/2008/12/30/euler-problem-19/#comment-36795 Hans Schraven Fri, 02 Jan 2009 23:38:00 +0000 http://www.dailydoseofexcel.com/?p=1928#comment-36795 <p>What about:</p> <div style="overflow: auto; white-space: nowrap;" class="codecolorer-container vb default"><div style="white-space: nowrap;" class="vb codecolorer"><span class="kw1">For</span> j = 0 <span class="kw1">To</span> 1200<br>   <span class="kw1">If</span> Format(DateAdd(<span class="st0">"m"</span>, j, <span class="st0">"01-01-1900"</span>), <span class="st0">"w"</span>) = 1 <span class="kw1">Then</span> x = x + 1<br> <span class="kw1">Next</span></div></div> What about:

For j = 0 To 1200
  If Format(DateAdd(“m”, j, “01-01-1900″), “w”) = 1 Then x = x + 1
Next
]]> By: Route 55 (and Route 19) « Grumpy Old Programmer http://www.dailydoseofexcel.com/archives/2008/12/30/euler-problem-19/#comment-36792 Route 55 (and Route 19) « Grumpy Old Programmer Fri, 02 Jan 2009 21:03:00 +0000 http://www.dailydoseofexcel.com/?p=1928#comment-36792 <p>[...] the other hand, VBA has the edge on problem 19. I spotted a little optimisation in Michael's code, which gave me this in VBA, which is about 20 times faster at 0.0019 seconds than the [...]</p> [...] the other hand, VBA has the edge on problem 19. I spotted a little optimisation in Michael’s code, which gave me this in VBA, which is about 20 times faster at 0.0019 seconds than the [...]

]]> By: Michael http://www.dailydoseofexcel.com/archives/2008/12/30/euler-problem-19/#comment-36789 Michael Fri, 02 Jan 2009 18:39:00 +0000 http://www.dailydoseofexcel.com/?p=1928#comment-36789 <p>Tushar -</p> <p>Do you have a link on your website to your large arithmetic functions?</p> <p>Happy New Year!</p> <p>...mrt</p> Tushar -

Do you have a link on your website to your large arithmetic functions?

Happy New Year!

…mrt

]]> By: Mike Woodhouse http://www.dailydoseofexcel.com/archives/2008/12/30/euler-problem-19/#comment-36786 Mike Woodhouse Fri, 02 Jan 2009 12:00:00 +0000 http://www.dailydoseofexcel.com/?p=1928#comment-36786 <p>The code as written is examining an awful lot of irrelevant dates, since we only want the first of each month. Changing the loop to </p> <p> If Weekday(Start) = vbSunday Then<br> Answer = Answer + 1<br> End If<br> Start = DateSerial(Year(Start), Month(Start) + 1, 1)</p> <p>is about 20 times faster on my machine (0.001875 vs 0.035625). Not 30-odd, I imagine, because the DateSerial business is more expensive than incrementing.</p> The code as written is examining an awful lot of irrelevant dates, since we only want the first of each month. Changing the loop to

If Weekday(Start) = vbSunday Then
Answer = Answer + 1
End If
Start = DateSerial(Year(Start), Month(Start) + 1, 1)

is about 20 times faster on my machine (0.001875 vs 0.035625). Not 30-odd, I imagine, because the DateSerial business is more expensive than incrementing.

]]> By: Tushar Mehta http://www.dailydoseofexcel.com/archives/2008/12/30/euler-problem-19/#comment-36774 Tushar Mehta Fri, 02 Jan 2009 00:58:00 +0000 http://www.dailydoseofexcel.com/?p=1928#comment-36774 <p>Or, use the Excel formula =SUMPRODUCT(–(WEEKDAY(DATE(1901,ROW(INDIRECT("1:1200?)),1))=1)) See <a href="http://www.tushar-mehta.com/misc_tutorials/project_euler/euler019.html" rel="nofollow">http://www.tushar-mehta.com/misc_tutorials/project_euler/euler019.html</a></p> Or, use the Excel formula =SUMPRODUCT(–(WEEKDAY(DATE(1901,ROW(INDIRECT(“1:1200?)),1))=1)) See http://www.tushar-mehta.com/misc_tutorials/project_euler/euler019.html

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