Code Golf: Prime Factors of a Number [closed]

Answer 1

C# and LINQ, 241 Characters:

public IEnumerable F(int n)
{
    return Enumerable.Range(2,n-1)
        .Where(x => (n%x)==0 && F(x).Count()==1)
        .Take(1)
        .SelectMany(x => new[]{x}.Concat(F(n/x)))
        .DefaultIfEmpty(n);
}

public string Factor(int n) {
    return F(n).Aggregate("", (s,i) => s+"x"+i).TrimStart('x'); 
}

Compressed:

int[] F(int n){return Enumerable.Range(2,n-1).Where(x=>(n%x)==0&&F(x).Length==1).Take(1).SelectMany(x=>new[]{x}.Concat(F(n/x))).DefaultIfEmpty(n).ToArray();}void G(int n){Console.WriteLine(F(n).Aggregate("",(s,i)=>s+"x"+i).TrimStart('x'));}