The number N is a string of decimal digits in which every digit is a difference between two other digits.
Examples: 333012 is such a number. So is 1278990.
What is the smallest pandigital number that possesses the above feature?
(In reply to
re: Solution by Ady TZIDON)
Ady, you may need to say more. I came to a solution 10023456789 (your intended?) but did not post it once I saw tomarken's.
On reading the reasoning behind his solution 10234567899 I decided mine was wrong. Why? It says the difference must be between "two other digits." So if there's a 9, it cannot be used in the difference that yields 9. There must be another 9.
Your examples bear this out: 333012 has more than one 3 and 1278990 has more than one 9. I figured this was why.

Posted by Jer
on 20160504 21:07:23 