Pandigital fun

[Paul Dale]

Have a look at this paper.

Pandigital representations of numbers up to 11111 where the digits are in ascending or descending order and only basic operations are used.

Code:

41 = 12 − 34 − 5 + 67 − 8 + 9

Pauli

[pier4r]

Just saw a video on numberphile about this and I wanted to create a programming challenge (limited to 3 digits numbers, that is already enough for a calculator).

But you spoiled it . Well no, I can do it nevertheless using the paper for checking the solutions.

[Gerson W. Barbosa]

(04-20-2017 10:48 AM)pier4r Wrote:  Just saw a video on numberphile about this and I wanted to create a programming challenge (limited to 3 digits numbers, that is already enough for a calculator).

What about another kind of fun?

Evaluate this:



Evaluate that:



Random order and ascending order. Descending order still missing...

[pier4r]

Well Gerson, while computing Pi in that way is fun, to me it is already a challenge to break down numbers.

In particular I like the idea of using only one digit and the four operations (plus powers and parentheses).

For example given 998 and 1.

998 = (11-1)^(1+1+1)- 1 -1

The hard part: having the smallest number of 1s used on the right side. And then doing the same with 2, 3 and so on. The mentioned video links to a paper with the solutions. It is still a nice challenge, so I will formalize it in some days. Calculator wise (we don't want to use the modern home supercomputers, do we?)