day 8 work and jumbled together

utils/bits/bits.go

@@ -0,0 +1,54 @@
+package bits
+
+func GetBitCount(val int) int {
+	count := 0
+	for val != 0 {
+		count += val & 1
+		val >>= 1
+	}
+
+	return count
+}
+
+// returns the number of matching bits in the two value's binary expression
+func MatchingOnBits(v1 int, v2 int) int {
+	count := 0
+	for v1 != 0 && v2 != 0 {
+		if v1&1 == 1 && v2&1 == 1 {
+			count += 1
+		}
+		v1 >>= 1
+		v2 >>= 1
+	}
+
+	return count
+}
+
+func BitwiseAnd(v1 int, v2 int) int {
+	val := 0
+	for block := 1; v1 != 0 || v2 != 0; block <<= 1 {
+		if v1&1 == 1 || v2&1 == 1 {
+			val += block
+		}
+		if v1 > 0 {
+			v1 >>= 1
+		}
+		if v2 > 0 {
+			v2 >>= 1
+		}
+	}
+	return val
+}
+
+func BitwiseAndA(a ...int) int {
+	total := 0
+	for _, i := range a {
+		total = BitwiseAnd(total, i)
+	}
+
+	return total
+}
+
+func ByBitCount(size int) func(int) bool {
+	return func(val int) bool { return GetBitCount(val) == size }
+}