1.0 KiB
1.0 KiB
id | title | challengeType | forumTopicId |
---|---|---|---|
5900f4371000cf542c50ff49 | Problem 202: Laserbeam | 5 | 301843 |
--description--
Three mirrors are arranged in the shape of an equilateral triangle, with their reflective surfaces pointing inwards. There is an infinitesimal gap at each vertex of the triangle through which a laser beam may pass.
Label the vertices A, B and C. There are 2 ways in which a laser beam may enter vertex C, bounce off 11 surfaces, then exit through the same vertex: one way is shown below; the other is the reverse of that.
There are 80840 ways in which a laser beam may enter vertex C, bounce off 1000001 surfaces, then exit through the same vertex.
In how many ways can a laser beam enter at vertex C, bounce off 12017639147 surfaces, then exit through the same vertex?
--hints--
euler202()
should return 1209002624.
assert.strictEqual(euler202(), 1209002624);
--seed--
--seed-contents--
function euler202() {
return true;
}
euler202();
--solutions--
// solution required