GET "libhdr"

LET choose(n, k) =
	~(0 <= k <= n) -> 0,
	2*k > n -> binomial(n, n - k),
	binomial(n, k)

AND binomial(n, k) =
	k = 0 -> 1,
	binomial(n, k - 1) * (n - k + 1) / k

LET start() = VALOF {
    LET n, k = ?, ?
    LET argv = VEC 20
    LET sz = ?

    sz := rdargs("n/a/n/p,k/a/n/p", argv, 20)
    UNLESS sz ~= 0 RESULTIS 1

    n := !argv!0
    k := !argv!1

    writef("%d  choose %d  = %d *n", n, k, choose(n, k))
    RESULTIS 0
}