Separate validateBitZeros into a separate file

1 files changed, 21 insertions, 0 deletions

diff --git a/bitwise.go b/bitwise.go
new file mode 100644
index 0000000..b9b6f47
--- /dev/null
+++ b/bitwise.go
@@ -0,0 +1,21 @@
+package main
+
+func validateBitZeros(bs []byte, n uint) bool {
+	q := n / 8
+	r := n % 8
+
+	for i := uint(0); i < q; i++ {
+		if bs[i] != 0 {
+			return false
+		}
+	}
+
+	if r > 0 {
+		mask := byte(0xFF << (8 - r))
+		if bs[q]&mask != 0 {
+			return false
+		}
+	}
+
+	return true
+}