func Benchmark1e8(b *testing.B) {
for i := 0; i < b.N; i++ {
sieve.New(1e8).Iterate(1, 1e8, func(uint64) (terminate bool) {
return
})
}
}
// Test the two generic access functions in prime.go, Primes() and
// Iterator(). Also test that the generators agree on all primes under
// a somewhat bigger limit.
//
// Use basic sieve as a reference, compare it to other generators.
func TestGeneric(t *testing.T) {
const limit = 1000
// exercise generic function Primes on sieve.
reference := prime.Primes(sieve.New(limit), 0, limit)
gloop:
for _, gen := range []prime.Generator{
segment.New(limit),
queue.PQueue{},
sprp.New(),
} {
// exercise generic function Iterator on other generators.
ch := prime.Iterator(gen, 0, limit)
for i, pRef := range reference {
switch p, ok := <-ch; {
case !ok:
t.Errorf("%s.Iterator(0, %d) didn't find all primes.",
reflect.TypeOf(gen), limit)
continue gloop
case p != pRef:
t.Errorf("%dth prime? sieve says %d, %s says %d\n",
i+1, pRef, reflect.TypeOf(gen), p)
continue gloop
}
}
if _, ok := <-ch; ok {
t.Errorf("%s.Iterator(0, %d) returning too many primes.\n",
reflect.TypeOf(gen), limit)
}
}
}
func TestBinomialS(t *testing.T) {
p := sieve.New(uint64(tcs[len(tcs)-1].n))
var b big.Int
for _, tc := range tcs {
if a := binomial.BinomialS(&b, p, tc.n, tc.k).String(); a != tc.s {
t.Error("Binomial(%d, %d) expected %s, got %s", tc.n, tc.k, tc.s, a)
}
}
}
// a little different that the generic test a directory up. creates sieves
// with different limits, starts iterating at 1, verifies number of primes.
func TestSieve(t *testing.T) {
for _, tc := range tcs {
var count uint64
sieve.New(tc.n).Iterate(1, tc.n, func(uint64) (terminate bool) {
count++
return
})
if count != tc.nPrimes {
t.Errorf("Wrong number of primes <= %d. expected %d, found %d",
tc.n, tc.nPrimes, count)
}
}
}
func BenchmarkBinomial1e6(b *testing.B) {
var c big.Int
for i := 0; i < b.N; i++ {
binomial.Binomial(&c, 1e6, uint(1e6)/3)
}
}
func BenchmarkBinomial2e6(b *testing.B) {
var c big.Int
for i := 0; i < b.N; i++ {
binomial.Binomial(&c, 2e6, uint(2e6)/3)
}
}
var p = sieve.New(2e6)
func BenchmarkBinomialS1e2(b *testing.B) {
var c big.Int
for i := 0; i < b.N; i++ {
binomial.BinomialS(&c, p, 1e2, uint(1e2)/3)
}
}
func BenchmarkBinomialS1e3(b *testing.B) {
var c big.Int
for i := 0; i < b.N; i++ {
binomial.BinomialS(&c, p, 1e3, uint(1e3)/3)
}
}
// Exercise Limit and Iterate methods of each implemented generator.
func TestMethods(t *testing.T) {
t100(t, segment.New(100))
t100(t, sieve.New(100))
t100(t, queue.PQueue{})
t100(t, sprp.New())
}
// New is a constructor that generates the underlying prime sieve.
// (If you have a sieve already, you can just assign the Sieve member of
// a zero value Swing object.)
func New(n uint) *Swing {
return &Swing{Sieve: sieve.New(uint64(n))}
}
// Binomal computes the binomial coefficient C(n,k) leaving the result in z.
// It replaces the existing value of z and returns z.
func Binomial(z *big.Int, n, k uint) *big.Int {
if k > n {
return z.SetInt64(0)
}
return BinomialS(z, sieve.New(uint64(n)), n, k)
}