freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-113-non-bouncy-numbers.english.md

id, challengeType, title, forumTopicId

id	challengeType	title	forumTopicId
5900f3dd1000cf542c50fef0	5	Problem 113: Non-bouncy numbers	301739

Description

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. As n increases, the proportion of bouncy numbers below n increases such that there are only 12951 numbers below one-million that are not bouncy and only 277032 non-bouncy numbers below 1010. How many numbers below a googol (10100) are not bouncy?

Instructions

Tests

tests:
  - text: <code>euler113()</code> should return 51161058134250.
    testString: assert.strictEqual(euler113(), 51161058134250);

Challenge Seed

function euler113() {
  // Good luck!
  return true;
}

euler113();

Solution

// solution required