CodeWars可以学习的

using System;
using System.Linq;

public static class Kata
{
public static int GetVowelCount(string str)
{
return str.Count(x => "aeiou".IndexOf(x) != -1);
}
}

public static class Kata
{
public static int GetVowelCount(string str)
{
return str.Where(c => new [] {'a','e','i','o','u'}.Any(v => v == c)).Count();
}
}

using System;

public class Evaporator {

public static int evaporator(double content, double evap_per_day, double threshold) {
return (int)Math.Ceiling(Math.Log(threshold / 100.0) / Math.Log(1.0 - evap_per_day / 100.0));
}
}