ee1e8abd87
* feat(tools): add seed/solution restore script * chore(curriculum): remove empty sections' markers * chore(curriculum): add seed + solution to Chinese * chore: remove old formatter * fix: update getChallenges parse translated challenges separately, without reference to the source * chore(curriculum): add dashedName to English * chore(curriculum): add dashedName to Chinese * refactor: remove unused challenge property 'name' * fix: relax dashedName requirement * fix: stray tag Remove stray `pre` tag from challenge file. Signed-off-by: nhcarrigan <nhcarrigan@gmail.com> Co-authored-by: nhcarrigan <nhcarrigan@gmail.com>
1.9 KiB
1.9 KiB
id, title, challengeType, forumTopicId, dashedName
| id | title | challengeType | forumTopicId | dashedName |
|---|---|---|---|---|
| 5e6dee7749a0b85a3f1fc7d5 | Lucas-Lehmer test | 5 | 385281 | lucas-lehmer-test |
--description--
Lucas-Lehmer Test: for p an odd prime, the Mersenne number 2^p-1 is prime if and only if 2^p-1 divides S(p-1) where S(n+1)=(S(n))^2-2, and S(1)=4.
--instructions--
Write a function that returns whether the given Mersenne number is prime or not.
--hints--
lucasLehmer should be a function.
assert(typeof lucasLehmer == 'function');
lucasLehmer(11) should return a boolean.
assert(typeof lucasLehmer(11) == 'boolean');
lucasLehmer(11) should return false.
assert.equal(lucasLehmer(11), false);
lucasLehmer(15) should return false.
assert.equal(lucasLehmer(15), false);
lucasLehmer(13) should return true.
assert.equal(lucasLehmer(13), true);
lucasLehmer(17) should return true.
assert.equal(lucasLehmer(17), true);
lucasLehmer(19) should return true.
assert.equal(lucasLehmer(19), true);
lucasLehmer(21) should return false.
assert.equal(lucasLehmer(21), false);
--seed--
--seed-contents--
function lucasLehmer(p) {
}
--solutions--
function lucasLehmer(p) {
function isPrime(p) {
if (p == 2)
return true;
else if (p <= 1 || p % 2 == 0)
return false;
else {
var to = Math.sqrt(p);
for (var i = 3; i <= to; i += 2)
if (p % i == 0)
return false;
return true;
}
}
function isMersennePrime(p) {
if (p == 2)
return true;
else {
var m_p = Math.pow(2, p) - 1
var s = 4;
for (var i = 3; i <= p; i++)
s = (s * s - 2) % m_p
return s == 0;
}
}
return isPrime(p) && isMersennePrime(p)
}