From f246ed4e80ba1e01d208c3f24f37c45bf76cc85e Mon Sep 17 00:00:00 2001
From: "exercism-solutions-syncer[bot]"
 <211797793+exercism-solutions-syncer[bot]@users.noreply.github.com>
Date: Sun, 1 Feb 2026 13:41:07 +0000
Subject: [PATCH] [Sync Iteration] go/luhn/3

---
 solutions/go/luhn/3/luhn.go | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 solutions/go/luhn/3/luhn.go

diff --git a/solutions/go/luhn/3/luhn.go b/solutions/go/luhn/3/luhn.go
new file mode 100644
index 0000000..93861c4
--- /dev/null
+++ b/solutions/go/luhn/3/luhn.go
@@ -0,0 +1,31 @@
+package luhn
+
+func Valid(id string) bool {
+	var sum, size int
+	double := false
+	for i := len(id) - 1; i >= 0; i-- {
+		r := id[i]
+
+		if r == ' ' {
+			continue
+		}
+
+		if r < '0' || r > '9' {
+			return false
+		}
+
+		n := int(r - '0')
+		if double {
+			n *= 2
+			if n > 9 {
+				n -= 9
+			}
+		}
+		double = !double
+
+		sum += n
+		size++
+	}
+
+	return sum%10 == 0 && size > 1
+}