1.2 KiB
1.2 KiB
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
5900f42c1000cf542c50ff3f | Problem 192: Best Approximations | 5 | 301830 | problem-192-best-approximations |
--description--
Let x
be a real number.
A best approximation to x
for the denominator bound d
is a rational number \frac{r}{s}
in reduced form, with s ≤ d
, such that any rational number which is closer to x
than \frac{r}{s}
has a denominator larger than d
:
|\frac{p}{q} - x| < |\frac{r}{s} - x| ⇒ q > d
For example, the best approximation to \sqrt{13}
for the denominator bound 20
is \frac{18}{5}
and the best approximation to \sqrt{13}
for the denominator bound 30
is \frac{101}{28}
.
Find the sum of all denominators of the best approximations to \sqrt{n}
for the denominator bound {10}^{12}
, where n
is not a perfect square and 1 < n ≤ 100000
.
--hints--
bestApproximations()
should return 57060635927998344
.
assert.strictEqual(bestApproximations(), 57060635927998344);
--seed--
--seed-contents--
function bestApproximations() {
return true;
}
bestApproximations();
--solutions--
// solution required