C-Sharp/Algorithms/Sequences/BinomialSequence.cs at master · TheAlgorithms/C-Sharp · GitHub

Name: C-Sharp/Algorithms/Sequences/BinomialSequence.cs at master · TheAlgorithms/C-Sharp · GitHub
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usingSystem.Collections.Generic;
usingSystem.Numerics;

namespaceAlgorithms.Sequences;

/// <summary>
/// <para>
/// Sequence of binomial coefficients.
/// </para>
/// <para>
/// Wikipedia: https://en.wikipedia.org/wiki/Binomial_coefficient.
/// </para>
/// <para>
/// OEIS: http://oeis.org/A007318.
/// </para>
/// </summary>
publicclassBinomialSequence:ISequence
{
/// <summary>
/// Gets sequence of binomial coefficients.
/// </summary>
publicIEnumerable<BigInteger>Sequence
{
get
{
vari=0;

while(true)
{
varrow=GenerateRow(i);
foreach(varcoefficientinrow)
{
yieldreturncoefficient;
}

i++;
}
}
}

privatestaticBigIntegerBinomialCoefficient(longn,longk)
{
if(k==0||k==n)
{
returnnewBigInteger(1);
}

if(n<0)
{
returnnewBigInteger(0);
}

returnBinomialCoefficient(n-1,k)+BinomialCoefficient(n-1,k-1);
}

privatestaticIEnumerable<BigInteger>GenerateRow(longn)
{
longk=0;

while(k<=n)
{
yieldreturnBinomialCoefficient(n,k);
k++;
}
}
}