math-suite/Source/Calculator/MathHelper.cs

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2018-02-05 23:24:46 +00:00
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Calculator
{
public static class MathHelper
{
#region Combinations
public static double Combinations(double n, double k)
{
k = Math.Min(k, n - k);
double a = 1, b = 1;
for (int i = 1; i <= k; i++)
{
a *= n - i + 1;
b *= i;
}
return a / b;
}
#endregion
public static double Arrangements(double n, double k)
{
double a = 1;
for (int i = 0; i < k; i++) a *= n - i;
return a;
}
public static double Factorial(double n)
{
double a = 1;
for (int i = 1; i <= n; i++) a *= i;
return a;
}
}
}