Golang intsets.Sparse類代碼示例

// Intersects reports whether this points-to set and the
// argument points-to set contain common members.
func (x PointsToSet) Intersects(y PointsToSet) bool {
	if x.pts == nil || y.pts == nil {
		return false
	}
	// This takes Θ(|x|+|y|) time.
	var z intsets.Sparse
	z.Intersection(&x.pts.Sparse, &y.pts.Sparse)
	return !z.IsEmpty()
}

func TestFailFastOnShallowCopy(t *testing.T) {
	var x intsets.Sparse
	x.Insert(1)

	y := x // shallow copy (breaks representation invariants)
	defer func() {
		got := fmt.Sprint(recover())
		want := "A Sparse has been copied without (*Sparse).Copy()"
		if got != want {
			t.Error("shallow copy: recover() = %q, want %q", got, want)
		}
	}()
	y.String() // panics
	t.Error("didn't panic as expected")
}

func TestBitString(t *testing.T) {
	var set intsets.Sparse
	set.Insert(0)
	set.Insert(7)
	set.Insert(177)
	want := "10000001" + strings.Repeat("0", 169) + "1"
	if got := set.BitString(); got != want {
		t.Errorf("BitString: got %s, want %s", got, want)
	}
}

func TestTakeMin(t *testing.T) {
	var set intsets.Sparse
	set.Insert(456)
	set.Insert(123)
	set.Insert(789)
	set.Insert(-123)
	var got int
	for i, want := range []int{-123, 123, 456, 789} {
		if !set.TakeMin(&got) || got != want {
			t.Errorf("TakeMin #%d: got %d, want %d", i, got, want)
		}
	}
	if set.TakeMin(&got) {
		t.Errorf("%s.TakeMin returned true", set, got)
	}
	if err := set.Check(); err != nil {
		t.Fatalf("check: %s: %#v", err, &set)
	}
}

// Insert, Len, IsEmpty, Hash, Clear, AppendTo.
func TestMoreBasics(t *testing.T) {
	var set intsets.Sparse
	set.Insert(456)
	set.Insert(123)
	set.Insert(789)
	if set.Len() != 3 {
		t.Errorf("%s.Len: got %d, want 3", set, set.Len())
	}
	if set.IsEmpty() {
		t.Error("%s.IsEmpty: got true", set)
	}
	if !set.Has(123) {
		t.Error("%s.Has(123): got false", set)
	}
	if set.Has(1234) {
		t.Error("%s.Has(1234): got true", set)
	}
	got := set.AppendTo([]int{-1})
	if want := []int{-1, 123, 456, 789}; fmt.Sprint(got) != fmt.Sprint(want) {
		t.Error("%s.AppendTo: got %v, want %v", got, want)
	}

	set.Clear()

	if set.Len() != 0 {
		t.Errorf("Clear: got %d, want 0", set.Len())
	}
	if !set.IsEmpty() {
		t.Error("IsEmpty: got false")
	}
	if set.Has(123) {
		t.Error("%s.Has: got false", set)
	}
}

func BenchmarkSparseBitVector(b *testing.B) {
	prng := rand.New(rand.NewSource(0))
	for tries := 0; tries < b.N; tries++ {
		var x, y, z intsets.Sparse
		for i := 0; i < 1000; i++ {
			n := int(prng.Int()) % 10000
			if i%2 == 0 {
				x.Insert(n)
			} else {
				y.Insert(n)
			}
		}
		z.Union(&x, &y)
		z.Difference(&x, &y)
	}
}

func TestIntersectionWith(t *testing.T) {
	// Edge cases: the pairs (1,1), (1000,2000), (8000,4000)
	// exercise the <, >, == cases in IntersectionWith that the
	// TestSetOperations data is too dense to cover.
	var X, Y intsets.Sparse
	X.Insert(1)
	X.Insert(1000)
	X.Insert(8000)
	Y.Insert(1)
	Y.Insert(2000)
	Y.Insert(4000)
	X.IntersectionWith(&Y)
	if got, want := X.String(), "{1}"; got != want {
		t.Errorf("IntersectionWith: got %s, want %s", got, want)
	}
}

func TestBasics(t *testing.T) {
	var s intsets.Sparse
	if len := s.Len(); len != 0 {
		t.Errorf("Len({}): got %d, want 0", len)
	}
	if s := s.String(); s != "{}" {
		t.Errorf("String({}): got %q, want \"{}\"", s)
	}
	if s := s.BitString(); s != "0" {
		t.Errorf("BitString({}): got %q, want \"0\"", s)
	}
	if s.Has(3) {
		t.Errorf("Has(3): got true, want false")
	}
	if err := s.Check(); err != nil {
		t.Error(err)
	}

	if !s.Insert(3) {
		t.Errorf("Insert(3): got false, want true")
	}
	if max := s.Max(); max != 3 {
		t.Errorf("Max: got %d, want 3", max)
	}

	if !s.Insert(435) {
		t.Errorf("Insert(435): got false, want true")
	}
	if s := s.String(); s != "{3, 435}" {
		t.Errorf("String({3, 435}): got %q, want \"{3, 435}\"", s)
	}
	if max := s.Max(); max != 435 {
		t.Errorf("Max: got %d, want 435", max)
	}
	if len := s.Len(); len != 2 {
		t.Errorf("Len: got %d, want 2", len)
	}

	if !s.Remove(435) {
		t.Errorf("Remove(435): got false, want true")
	}
	if s := s.String(); s != "{3}" {
		t.Errorf("String({3}): got %q, want \"{3}\"", s)
	}
}

func TestEquals(t *testing.T) {
	var setX intsets.Sparse
	setX.Insert(456)
	setX.Insert(123)
	setX.Insert(789)

	if !setX.Equals(&setX) {
		t.Errorf("Equals(%s, %s): got false", &setX, &setX)
	}

	var setY intsets.Sparse
	setY.Insert(789)
	setY.Insert(456)
	setY.Insert(123)

	if !setX.Equals(&setY) {
		t.Errorf("Equals(%s, %s): got false", &setX, &setY)
	}

	setY.Insert(1)
	if setX.Equals(&setY) {
		t.Errorf("Equals(%s, %s): got true", &setX, &setY)
	}

	var empty intsets.Sparse
	if setX.Equals(&empty) {
		t.Errorf("Equals(%s, %s): got true", &setX, &empty)
	}

	// Edge case: some block (with offset=0) appears in X but not Y.
	setY.Remove(123)
	if setX.Equals(&setY) {
		t.Errorf("Equals(%s, %s): got true", &setX, &setY)
	}
}

func TestMinAndMax(t *testing.T) {
	values := []int{0, 456, 123, 789, -123} // elt 0 => empty set
	wantMax := []int{intsets.MinInt, 456, 456, 789, 789}
	wantMin := []int{intsets.MaxInt, 456, 123, 123, -123}

	var set intsets.Sparse
	for i, x := range values {
		if i != 0 {
			set.Insert(x)
		}
		if got, want := set.Min(), wantMin[i]; got != want {
			t.Errorf("Min #%d: got %d, want %d", i, got, want)
		}
		if got, want := set.Max(), wantMax[i]; got != want {
			t.Errorf("Max #%d: got %d, want %d", i, got, want)
		}
	}

	set.Insert(intsets.MinInt)
	if got, want := set.Min(), intsets.MinInt; got != want {
		t.Errorf("Min: got %d, want %d", got, want)
	}

	set.Insert(intsets.MaxInt)
	if got, want := set.Max(), intsets.MaxInt; got != want {
		t.Errorf("Max: got %d, want %d", got, want)
	}
}