Merge pull request #956 from vaskoz/day301

Day301

README.md

@@ -312,6 +312,7 @@ problems from
 * [Day 298](https://github.com/vaskoz/dailycodingproblem-go/issues/609)
 * [Day 299](https://github.com/vaskoz/dailycodingproblem-go/issues/611)
 * [Day 300](https://github.com/vaskoz/dailycodingproblem-go/issues/612)
+* [Day 301](https://github.com/vaskoz/dailycodingproblem-go/issues/613)
 * [Day 302](https://github.com/vaskoz/dailycodingproblem-go/issues/615)
 * [Day 303](https://github.com/vaskoz/dailycodingproblem-go/issues/616)
 * [Day 304](https://github.com/vaskoz/dailycodingproblem-go/issues/618)

day301/problem.go

@@ -0,0 +1,24 @@
+package day301
+
+import "github.com/algds/bloom"
+
+// BloomFilter encapsulates github.com/algds/bloom
+// to conform to method signatures.
+type BloomFilter struct {
+	blf bloom.Filter
+}
+
+// Add a value to the set of values.
+func (bf *BloomFilter) Add(value interface{}) {
+	bf.blf.Add(value)
+}
+
+// Check whether a value is in the set.
+func (bf *BloomFilter) Check(value interface{}) bool {
+	return bf.blf.Contains(value)
+}
+
+// NewBloomFilter creates a new instance of BloomFilter.
+func NewBloomFilter(m uint, hashes []bloom.Hash) *BloomFilter {
+	return &BloomFilter{blf: bloom.New(m, hashes...)}
+}

day301/problem_test.go

@@ -0,0 +1,62 @@
+package day301
+
+import (
+	"testing"
+
+	"github.com/algds/bloom"
+)
+
+func TestBloomFilter(t *testing.T) {
+	t.Parallel()
+
+	f1 := func(d interface{}) uint {
+		s := d.(string)
+
+		return uint(s[0])
+	}
+	f2 := func(d interface{}) uint {
+		s := d.(string)
+
+		return uint(s[1])
+	}
+
+	blf := NewBloomFilter(100, []bloom.Hash{f1, f2})
+
+	blf.Add("foo")
+	blf.Add("bar")
+
+	if !blf.Check("foo") {
+		t.Errorf("foo should be found")
+	}
+
+	if !blf.Check("bar") {
+		t.Errorf("bar should be found")
+	}
+
+	if blf.Check("xyz") {
+		t.Errorf("xyz should not be found")
+	}
+}
+
+func BenchmarkBloomFilter(b *testing.B) {
+	f1 := func(d interface{}) uint {
+		s := d.(string)
+
+		return uint(s[0])
+	}
+	f2 := func(d interface{}) uint {
+		s := d.(string)
+
+		return uint(s[1])
+	}
+
+	blf := NewBloomFilter(100, []bloom.Hash{f1, f2})
+
+	for i := 0; i < b.N; i++ {
+		blf.Add("foo")
+		blf.Add("bar")
+		blf.Check("foo")
+		blf.Check("bar")
+		blf.Check("xyz")
+	}
+}