Do you remember Dan Mayoh from the 'ModelOff World Excel Championships' held in December of 2012 [refer to Podcast #1610 -
]? Dan suggested the latest in 'The MrExcel Challenge' series. Follow along today with Bill "MrExcel" Jelen, in Episode #1695, as he lays out the the goal of this current MrExcel Challenge as well as all of the details and prizes!
Today's Podcast is sponsored by "Learn Excel 2007 through Excel 2010 from MrExcel". Download a new two minute video every workday to learn one of the 512 Excel Mysteries Solved! 35% More Tips than the previous edition of Bill's book! Power Excel With MrExcel - 2017 Edition
And if you are using Excel 2013, you may want to check out...
"Microsoft 2013 InDepth" -- by Bill Jelen. Excel 2013 In Depth is the beyond-the-basics, beneath-the-surface guide for everyone working with Excel 2013. Excel expert and MVP Bill Jelen provides specific, tested, proven solutions to the problems Excel users run into every day: the types of challenges other books ignore or oversimplify. Jelen thoroughly covers all facets of working with Excel 2013. Excel 2013 In Depth
"The Learn Excel from MrExcel Podcast Series"
MrExcel.com — Your One Stop for Excel Tips and Solutions. Visit us today!
Today's Podcast is sponsored by "Learn Excel 2007 through Excel 2010 from MrExcel". Download a new two minute video every workday to learn one of the 512 Excel Mysteries Solved! 35% More Tips than the previous edition of Bill's book! Power Excel With MrExcel - 2017 Edition
And if you are using Excel 2013, you may want to check out...
"Microsoft 2013 InDepth" -- by Bill Jelen. Excel 2013 In Depth is the beyond-the-basics, beneath-the-surface guide for everyone working with Excel 2013. Excel expert and MVP Bill Jelen provides specific, tested, proven solutions to the problems Excel users run into every day: the types of challenges other books ignore or oversimplify. Jelen thoroughly covers all facets of working with Excel 2013. Excel 2013 In Depth
"The Learn Excel from MrExcel Podcast Series"
MrExcel.com — Your One Stop for Excel Tips and Solutions. Visit us today!
Transcript of the video:
MrExcel podcast is sponsored by “Easy-XL”!
Learn Excel from MrExcel podcast, episode 1695 - Perfect Shuffle Challenge!
Hey, welcome back to the MrExcel netcast, I'm Bill Jelen.
Well, many years ago, we used to have the challenge of the month at MrExcel, and talking to Dan Mayoh.
Dan, as you might remember, did a couple of guest podcast for us, he was one of the model of Champions, and Dan proposed that we run this challenge of the month, and I think it's a great one, so.
A perfect shuffle of a deck of cards, is a trick used by magicians to give the illusion of randomness, when in fact the order the cards is being controlled.
You have to cut the deck into two exactly equal halves, and then perfectly interlace the two halves, one card at a time.
So, in a typical deck, 52 cards, let's number them from 1-52, the left half contains 1-26, the right half contains 27-52.
Then they're merged, from the bottom up, so the deck ends up in this order: 1, 27, 2, 28, 3, 29, and so on.
So, Here's the interesting thing, if you do a perfect shuffle 7 more times, that deck of 52 cards will be back in the original order.
Alright, so let's try it.
I have a little formula here, which I'm not going to reveal right now, that does the perfect shuffle, and we will do 8 of these.
So CTRL+C to copy, CTRL+V to paste.
Let's do a little conditional formatting here, Conditional Formatting, color scales, alright, so we can kind of see the patterns emerge.
And sure enough, Dan is correct, we started out here in 1-52, do a perfect shuffle 8 times, and you end up in exactly the same order.
Alright, so that's a useful for casinos to know, right?
Because if they have a card shark coming in, you know, anyway.
So, the goal for the challenge of the month here is, write an Excel spreadsheet to answer the following question: For each even-numbered deck sizes from 2 cards to 200 cards, what's the smallest number of perfect shuffles required so way the deck will be back in the original order?
Now, for 4 cards the answer is 2.
For 52 cards, we just saw, the answer is 8.
What about the other values?
Now, we're looking for the simplest and most elegant way of modeling this that you can.
Find interesting ways to display the answers, and highlight any patterns you may see emerging.
We're particularly interested.
Now Dan and I have each solved this in different ways for the 2-200, but is there a pattern that would allow us to create a formula that would do this for any number?
Like 20.000?
How many perfect shuffles do need to get 20.000 without actually modeling a 20.000-20.000 array?
So, that's not part of the challenge, but certainly bonus points for that.
Let's run it from April 24th, today, through May 22nd 2013, send your workbooks to Bill@MrExcel.com.
Now hey, that email address is down at the office on another computer, it's not checked every day, don't send me regular email there, just send the challenge entries there.
Judges will be myself, Dan Mayoh, and we'll find someone else.
Three prizes: Best without VBA, Best with VBA, and then most interesting.
And certainly, if someone can solve that 20.000, you know, like any number of deck, that would be interesting.
And, for prizes, so I just saw that Scott put a new bundle up at the store, the eBook bundle.
It looks like there's nine different eBooks there, everything from the most basic "Don't fear the Spreadsheet", through Bob Umlas' "Excel Outside the Box", and "Excel Gurus Gone Wild".
So something for everybody there, 99$ value, will ship these three eBook bundles to our winners.
So there you go, return of the challenge of the month, building a spreadsheet to model the perfect shuffle, for any size deck, from 2-200 cards!
Alright well hey, I want to thank you for stopping by, we'll see you next time for another netcast from MrExcel!
Learn Excel from MrExcel podcast, episode 1695 - Perfect Shuffle Challenge!
Hey, welcome back to the MrExcel netcast, I'm Bill Jelen.
Well, many years ago, we used to have the challenge of the month at MrExcel, and talking to Dan Mayoh.
Dan, as you might remember, did a couple of guest podcast for us, he was one of the model of Champions, and Dan proposed that we run this challenge of the month, and I think it's a great one, so.
A perfect shuffle of a deck of cards, is a trick used by magicians to give the illusion of randomness, when in fact the order the cards is being controlled.
You have to cut the deck into two exactly equal halves, and then perfectly interlace the two halves, one card at a time.
So, in a typical deck, 52 cards, let's number them from 1-52, the left half contains 1-26, the right half contains 27-52.
Then they're merged, from the bottom up, so the deck ends up in this order: 1, 27, 2, 28, 3, 29, and so on.
So, Here's the interesting thing, if you do a perfect shuffle 7 more times, that deck of 52 cards will be back in the original order.
Alright, so let's try it.
I have a little formula here, which I'm not going to reveal right now, that does the perfect shuffle, and we will do 8 of these.
So CTRL+C to copy, CTRL+V to paste.
Let's do a little conditional formatting here, Conditional Formatting, color scales, alright, so we can kind of see the patterns emerge.
And sure enough, Dan is correct, we started out here in 1-52, do a perfect shuffle 8 times, and you end up in exactly the same order.
Alright, so that's a useful for casinos to know, right?
Because if they have a card shark coming in, you know, anyway.
So, the goal for the challenge of the month here is, write an Excel spreadsheet to answer the following question: For each even-numbered deck sizes from 2 cards to 200 cards, what's the smallest number of perfect shuffles required so way the deck will be back in the original order?
Now, for 4 cards the answer is 2.
For 52 cards, we just saw, the answer is 8.
What about the other values?
Now, we're looking for the simplest and most elegant way of modeling this that you can.
Find interesting ways to display the answers, and highlight any patterns you may see emerging.
We're particularly interested.
Now Dan and I have each solved this in different ways for the 2-200, but is there a pattern that would allow us to create a formula that would do this for any number?
Like 20.000?
How many perfect shuffles do need to get 20.000 without actually modeling a 20.000-20.000 array?
So, that's not part of the challenge, but certainly bonus points for that.
Let's run it from April 24th, today, through May 22nd 2013, send your workbooks to Bill@MrExcel.com.
Now hey, that email address is down at the office on another computer, it's not checked every day, don't send me regular email there, just send the challenge entries there.
Judges will be myself, Dan Mayoh, and we'll find someone else.
Three prizes: Best without VBA, Best with VBA, and then most interesting.
And certainly, if someone can solve that 20.000, you know, like any number of deck, that would be interesting.
And, for prizes, so I just saw that Scott put a new bundle up at the store, the eBook bundle.
It looks like there's nine different eBooks there, everything from the most basic "Don't fear the Spreadsheet", through Bob Umlas' "Excel Outside the Box", and "Excel Gurus Gone Wild".
So something for everybody there, 99$ value, will ship these three eBook bundles to our winners.
So there you go, return of the challenge of the month, building a spreadsheet to model the perfect shuffle, for any size deck, from 2-200 cards!
Alright well hey, I want to thank you for stopping by, we'll see you next time for another netcast from MrExcel!
