Project Euler Forum

Hello.
I think I've found the solution to problem 32, but projecteuler.net rejects it.

Problem 32 asks:
"Find the sum of all products whose multiplicand/multiplier/product identity can be written as a 1 through 9 pandigital. "

I think these are the products:

[edit]Removed correct solution set[/edit]

and the sum of the products is _____, but it does not seem to be the answer.
What I'm doing wrong?

Thanks

I've edited your post to remove the list, as it is correct. Remember, the word product means the answer you get from multiplying. You might find the hint in the problem statement helpful.

Now I've got it 8-D
Thanks.

You're welcome, and congrats.

Am I getting it right that multiplicand/multiplier/product should have in total exactly nine digits?

Yes.

can anyone explain me what does "pandigital" mean?
thanks

Problem 41 (View Problem): We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once.

Good question, marco6. I hadn't realised that a definition was missing from that question. I've added the same definition from problem 41 (thanks, Georg) as an introduction to the problem.

Problem 32 (View Problem)

Thank you for your answer!

Mods: A very small typo in the last word of the first paragraph - "pandigitial".

Thanks - fixed.

Hello,
I think that I have found correct solution but ProjectEuler rejects it so I have a question:
For example is 39 x 186 = 7254 and 186 x 39 = 7254 counted as one or two different pandigital identities?

One. The problem clearly states:

HINT: Some products can be obtained in more than one way so be sure to only include it once in your sum.

Note that this is even stricter than just swapping the two factors.

Thanks, I omitted the word "once" while I was reading

Could someone explain to me what this problem is referring to by "identity"? I know it's meaning in other contexts, not this one.
Thanks in advance!

When you have an equal sign (=), it means that both sides must be considered identical. Thus, 39 × 186 can be considered an identity of 7254. Similarly 78 x 93, 31 x 234 and 13 x 18 x 31 would also be considered identities of 7254 among many others.

Do we have to consider solutions with multiple multiplicands?
X * Y * Z = U

?

Spura wrote:Do we have to consider solutions with multiple multiplicands?
X * Y * Z = U

?

No

Spura wrote:Do we have to consider solutions with multiple multiplicands?
X * Y * Z = U

?

No, only Multiplicand * Multiplier = Product
Problem 32 (View Problem)