Problem 42377. Bouncy numbers
Inspired by Project Euler n°112.
- Working from left-to-right if no digit is exceeded by the digit to its left it is called an increasing number. For example: 134468.
- Similarly if no digit is exceeded by the digit to its right it is called a decreasing number. For example: 66420.
We shall call a positive integer that is neither increasing nor decreasing a bouncy number. For example, 155349.
Clearly there cannot be any bouncy numbers below one-hundred, but surprisingly, these numbers become more and more common after.
Find the least number for which the proportion of bouncy numbers is exactly p%.
As always this type of problem is difficult to solve with usual Matlab functions (num2str).
So keep an eye on time...
Solution Stats
Problem Comments
-
2 Comments
James
on 15 Jun 2015
I think the problem statement should read "the proportion of bouncy numbers is at least p%", rather than "exactly p%."
Rafael S.T. Vieira
on 9 Aug 2020
Currently, num2str is able to handle all test cases.
Solution Comments
Show commentsProblem Recent Solvers36
Suggested Problems
-
Extract leading non-zero digit
2135 Solvers
-
The Goldbach Conjecture, Part 2
2334 Solvers
-
357 Solvers
-
5522 Solvers
-
Find the sides of an isosceles triangle when given its area and height from its base to apex
1911 Solvers
More from this Author43
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!