805 B
805 B
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
5900f4e11000cf542c50fff3 | Problem 372: Pencils of rays | 5 | 302034 | problem-372-pencils-of-rays |
--description--
Let R(M, N)
be the number of lattice points (x
, y
) which satisfy M \lt x \le N
, M \lt y \le N
and \left\lfloor\frac{y^2}{x^2}\right\rfloor
is odd.
We can verify that R(0, 100) = 3\\,019
and R(100, 10\\,000) = 29\\,750\\,422
.
Find R(2 \times {10}^6, {10}^9)
.
Note: \lfloor x\rfloor
represents the floor function.
--hints--
pencilsOfRays()
should return 301450082318807040
.
assert.strictEqual(pencilsOfRays(), 301450082318807040);
--seed--
--seed-contents--
function pencilsOfRays() {
return true;
}
pencilsOfRays();
--solutions--
// solution required