Sha256: 3054e3a5ebfedae8b3adcd6858dac6d6061615d7a9287bc6817fde6fdc33e114
Contents?: true
Size: 881 Bytes
Versions: 271
Compression:
Stored size: 881 Bytes
Contents
using System;
using System.Collections.Generic;
using System.Linq;
public static class NthPrime
{
public static int Prime(int nth)
{
if (nth < 1)
throw new ArgumentOutOfRangeException();
return Primes().Skip(nth - 1).First();
}
private static IEnumerable<int> Primes()
{
yield return 2;
yield return 3;
foreach (var prime in PossiblePrimes().Where(IsPrime))
{
yield return prime;
}
}
private static IEnumerable<int> PossiblePrimes()
{
var n = 6;
while (true)
{
yield return n - 1;
yield return n + 1;
n += 6;
}
}
private static bool IsPrime(int n)
{
var r = (int)Math.Floor(Math.Sqrt(n));
return r < 5 || Enumerable.Range(5, r - 4).All(x => n % x != 0);
}
}
Version data entries
271 entries across 271 versions & 1 rubygems