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gikf 5a52c229f5 fix(curriculum): clean-up Project Euler 181-200 (#42819)
* fix: clean-up Project Euler 181-200

* fix: corrections from review

Co-authored-by: Tom <20648924+moT01@users.noreply.github.com>

* fix: missing delimiter

Co-authored-by: Tom <20648924+moT01@users.noreply.github.com>
2021-07-15 15:52:14 +02:00

1.2 KiB

id, title, challengeType, forumTopicId, dashedName
id title challengeType forumTopicId dashedName
5900f4331000cf542c50ff45 Problem 198: Ambiguous Numbers 5 301836 problem-198-ambiguous-numbers

--description--

A best approximation to a real number x for the denominator bound d is a rational number \frac{r}{s} (in reduced form) with s ≤ d, so that any rational number \frac{p}{q} which is closer to x than \frac{r}{s} has q > d.

Usually the best approximation to a real number is uniquely determined for all denominator bounds. However, there are some exceptions, e.g. \frac{9}{40} has the two best approximations \frac{1}{4} and \frac{1}{5} for the denominator bound 6. We shall call a real number x ambiguous, if there is at least one denominator bound for which x possesses two best approximations. Clearly, an ambiguous number is necessarily rational.

How many ambiguous numbers x = \frac{p}{q}, 0 &lt; x &lt; \frac{1}{100}, are there whose denominator q does not exceed {10}^8?

--hints--

ambiguousNumbers() should return 52374425.

assert.strictEqual(ambiguousNumbers(), 52374425);

--seed--

--seed-contents--

function ambiguousNumbers() {

  return true;
}

ambiguousNumbers();

--solutions--

// solution required