Merge pull request #236 from swnb/master

add (bitmap) : add bitmap of golang

go/45_bitmap/bitmap.go

@@ -0,0 +1,29 @@
+package bitmap
+
+// BitMap implement bitmap
+type BitMap []byte
+
+// New create BitMap
+func New(length uint) BitMap {
+	return make([]byte, length/8+1)
+}
+
+// Set set value in bitmap
+func (b BitMap) Set(value uint) {
+	byteIndex := value / 8
+	if byteIndex >= uint(len(b)) {
+		return
+	}
+	bitIndex := value % 8
+	[]byte(b)[byteIndex] |= 1 << bitIndex
+}
+
+// Get check whether value exist or not
+func (b BitMap) Get(value uint) bool {
+	byteIndex := value / 8
+	if byteIndex >= uint(len(b)) {
+		return false
+	}
+	bitIndex := value % 8
+	return []byte(b)[byteIndex]&(1<<bitIndex) != 0
+}

go/45_bitmap/bitmap_test.go

@@ -0,0 +1,15 @@
+package bitmap
+
+import (
+	"testing"
+)
+
+func TestBitMap(t *testing.T) {
+	bitMap := New(80)
+	for i := 0; i <= 100; i += 10 {
+		bitMap.Set(uint(i))
+	}
+	for i := 0; i <= 100; i += 10 {
+		t.Log(bitMap.Get(uint(i)))
+	}
+}