freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-469-empty-chairs.english.md

id, challengeType, isHidden, title, forumTopicId

id	challengeType	isHidden	title	forumTopicId
5900f5411000cf542c510053	5	false	Problem 469: Empty chairs	302144

Description

In a room N chairs are placed around a round table. Knights enter the room one by one and choose at random an available empty chair. To have enough elbow room the knights always leave at least one empty chair between each other.

When there aren't any suitable chairs left, the fraction C of empty chairs is determined. We also define E(N) as the expected value of C. We can verify that E(4) = 1/2 and E(6) = 5/9.

Find E(1018). Give your answer rounded to fourteen decimal places in the form 0.abcdefghijklmn.

Instructions

Tests

tests:
  - text: <code>euler469()</code> should return 0.56766764161831.
    testString: assert.strictEqual(euler469(), 0.56766764161831);

Challenge Seed

function euler469() {
  // Good luck!
  return true;
}

euler469();

Solution

// solution required