public static M Sum <M>(this IAdditiveMonoid <M> g, IEnumerable <M> source)
{
var sum = g.Zero();
foreach (var value in source)
{
sum = g.Add(sum, value);
}
return(sum);
}
//For this definition one should usually assume that IAdditiveMonoid<M> is abelian
public static M ScalarMult <M>(this IAdditiveMonoid <M> g, int n, M a)
{
if (n < 0)
{
throw new ArgumentException($"n={n} < 0!");
}
var res = g.Zero();
for (var i = 0; i < n; i++)
{
res = g.Add(res, a);
}
return(res);
}
public static M Sum <M>(this IAdditiveMonoid <M> g, params M[] source)
{
return(g.Sum(source.ToList()));
}
public static M SumNSmallest <M>(this IAdditiveMonoid <M> g, IEnumerable <M> source, int n)
{
var nsmallest = g.GetNSmallest(source, n);
return(g.Sum(nsmallest));
}
