func TestSubsetOf(t *testing.T) {
prng := rand.New(rand.NewSource(0))
for i := uint(0); i < 12; i++ {
X, Y := randomPset(prng, 1<<i), randomPset(prng, 1<<i)
x, y := &X.bits, &Y.bits
// test the slow way
var z intsets.Sparse
z.Copy(x)
z.DifferenceWith(y)
if got, want := x.SubsetOf(y), z.IsEmpty(); got != want {
t.Errorf("SubsetOf: got %v, want %v", got, want)
}
// make it true
y.UnionWith(x)
if got, want := x.SubsetOf(y), true; got != want {
t.Errorf("SubsetOf: got %v, want %v", got, want)
}
// make it false
if x.IsEmpty() {
continue
}
a := x.AppendTo(nil)
i := prng.Intn(len(a))
y.Remove(a[i])
if got, want := x.SubsetOf(y), false; got != want {
t.Errorf("SubsetOf: got %v, want %v", got, want)
}
}
}