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        riddles >> hard >> 2003 - an odissey with pi and e
        
(Message started by: pcbouhid on Nov 20^th, 2005, 12:23pm)

Title: 2003 - an odissey with pi and e
Post by pcbouhid on Nov 20^th, 2005, 12:23pm

These are the initials decimals of pi and e:

Decimals of pi: 1415926535897932384626433832795...
Decimals of e : 7182818284590452353602874713526...

Without rearranging the order of the digits, add any quantity of parentheses and arithmetic signs +, -, *, / (with same manner in both line) so that to make correct arithmetic expressions equally to 2003, using the least possible number of symbols. You have to use the digits starting from the left one, and the same numbers of digits in each case.

Example for number 11, using the first 5 digits:

- (1 * 4) + 1 + 5 + 9 = 11
- (7 * 1) + 8 + 2 + 8 = 11

These two expression contains, at its left size, 12 symbols (5 digits, 2 parentheses and 5 arithmetic signs).

Title: Re: 2003 - an odissey with pi and e
Post by JohanC on Nov 20^th, 2005, 1:11pm

I'm perplex. Only 12 digits/21 symbols?

Title: Re: 2003 - an odissey with pi and e
Post by JocK on Nov 20^th, 2005, 1:47pm

on 11/20/05 at 13:11:16, JohanC wrote:

I'm perplex. Only 12 digits/21 symbols?

What is meant, I think, is 12 symbols on the LHS of each of the example equations...

Title: Re: 2003 - an odissey with pi and e
Post by pcbouhid on Nov 20^th, 2005, 2:12pm

Right, Jock!

I´m back. In the bath I realize what you are saying. What a small world, isn´t JohanC?

Title: Re: 2003 - an odissey with pi and e
Post by JohanC on Nov 20^th, 2005, 3:19pm

Indeed.
I get the impression that it is only solvable writing some quite special-purpose computer program.

Title: Re: 2003 - an odissey with pi and e
Post by pcbouhid on Nov 20^th, 2005, 4:29pm

Don´t you think that´s easier to cut and paste?

Title: Re: 2003 - an odissey with pi and e
Post by Barukh on Nov 21^st, 2005, 12:45am

Can you stick the digits together to form a multi-digit number?

Title: Re: 2003 - an odissey with pi and e
Post by pcbouhid on Nov 21^st, 2005, 2:16am

Yes, Barukh, you can take for example, when using pi, the number 14 or 141, etc...

I´ll write here, the number of digits you have to use (if you need a hint):[hide]12[/hide]

Title: Re: 2003 - an odissey with pi and e
Post by Barukh on Nov 21^st, 2005, 11:36pm

[hide]2003 = 7 * (18 * 2 - 8 + 18) + 2 * 845 - 9 = 1 * (41 * 5 - 9 + 26) + 5 * 358 - 9[/hide],

and I agree with JohanC about the approach to the solution.

Title: Re: 2003 - an odissey with pi and e
Post by JohanC on Nov 22^nd, 2005, 1:09am

Another approach is using Google, which leads you to a forum called perplexus.info, and which besides your solution also lists a solution using the same number of "symbols", but one digit more:
[hide]1 * 4 + 1 * 59 * 2 - 6 + 5 * 358 + 97 = 2003
7 * 1 + 8 * 28 * 1 - 8 + 2 * 845 + 90 = 2003[/hide]

Title: Re: 2003 - an odissey with pi and e
Post by pcbouhid on Nov 22^nd, 2005, 9:34am

Barukh, now you can realize what JohanC were saying. Look at his comment, and look at the name of the site.

BTW JohanC, you know who I am, are you JC? My impression is reinforced by your comment about using a computer.

Title: Re: 2003 - an odissey with pi and e
Post by Barukh on Nov 22^nd, 2005, 11:39am

pcbouhid, I didn't know about this portal, but I did have a "special purpose" software which I wrote a year a so ago for a no less difficult problem posted here.

I don't get the connection beetween JohanC's original remark and the name of that site. However, I do see what you meant by writing:

on 11/20/05 at 16:29:47, pcbouhid wrote:

Don´t you think that´s easier to cut and paste?

By the way, this perplexus.info site looks intriguing! Who is running it? How would you compare it to this forum?

Title: Re: 2003 - an odissey with pi and e
Post by JohanC on Nov 22^nd, 2005, 11:48am

Hi, Pcbouhid,
There are many JCs in the world, but I'm not the JC you knew before.
It's always interesting to know one JC more.
Do you think it is coincidence so many well-known people share the same initials? (Jesus Chirst, John Cleese, Julius Caesar, Jimmy Carter, ...)

Title: Re: 2003 - an odissey with pi and e
Post by towr on Nov 22^nd, 2005, 12:17pm

on 11/22/05 at 11:39:37, Barukh wrote:

I don't get the connection beetween JohanC's original remark and the name of that site.

He was perplex, the site is perplexus.. Seems like that might be a connection.. ::)

Title: Re: 2003 - an odissey with pi and e
Post by pcbouhid on Nov 23^rd, 2005, 4:59am

First, to towr: obviously there´s a connection. JohanC knows me from that site, perplexus.info, where I´m a regular contributor. The JC I´m reffering to, I knew there, and he´s out a long time. In that site, in most of the problems I submit I always ask to not use a computer. Coincidence his comment about using a computer? I don´t think so.

Barukh, perplexus.info it´s a good British site, run by Levik. It was the first site I knew, and it has some, let´s say, facilities, that we don´t have here. I made a suggestion to this site, but Icarus told me that WW was too busy for any changes now. In Perplexus.info, we don´t receive an email to knew about any new comment in one problem. We simply "put" in what is called "my watch list" the problems that we want to follow. Thus, after entering the site, all we need to do is first see if there is a new problem "in the air", and then consult our "watch list" to see if anything new happenened with the problems in it.

In Perplexus, the users can submit as much as problems as they want, that enter in a queue (today there are about 300 problems in the queue), but before one problem is released, it is analyzed by a group called Journeyman, that votes YES or NO (one problem must receive 3 YES), after a discussion that you can follow if you are the submitter, even to clarify the text, etc...

And, also in Perplexus, the problems are classified in cathegories, like "just math", "logic", cryptography", "word problems", "riddles", "calculus" etc... and there are 5 levels of difficulty (from 1 to 5).

I think that you (and towr) should take a look. It´s a very good site, and I made some good friends there (I´m brazilian).

Finally, I´m sure that JohanC it´s that JC, but I don´t know why he´s hidding himself. Even his last comment makes me more sure.

Feel free to make any more questions.

Cheers,
Paulo

Title: Re: 2003 - an odissey with pi and e
Post by towr on Nov 23^rd, 2005, 5:26am

I've been to that site a few times a long while ago. But I failed to keep track of it. It didn't really appeal to me for some reason.

Title: Re: 2003 - an odissey with pi and e
Post by JocK on Nov 23^rd, 2005, 10:32am

on 11/23/05 at 05:26:45, towr wrote:

It didn't really appeal to me for some reason.

I think I can guess what that reason was...

Just tried to visit www.perplexus.info. This instantly activated my pop-up blocker. Strangely enough one pop-up came through, and my browser crashed...

Title: Re: 2003 - an odissey with pi and e
Post by towr on Nov 23^rd, 2005, 1:57pm

on 11/23/05 at 10:32:04, JocK wrote:

I think I can guess what that reason was...

Just tried to visit www.perplexus.info. This instantly activated my pop-up blocker. Strangely enough one pop-up came through, and my browser crashed...

That wasn't the case then, I think.
But it's certainly an offputting 'feature'.

The one that got through might be from a flash exploit. Advertisers have found a few new ways to popup ads lately. But banning the ad servers it comes from should work.