Add MTC to output

(MTC = Multiplication Table Complexity)

1 files changed, 19 insertions, 0 deletions

diff --git a/factors/mtc.go b/factors/mtc.go
new file mode 100644
index 0000000..d008ca3
--- /dev/null
+++ b/factors/mtc.go
@@ -0,0 +1,19 @@
+package factors
+
+// MTC returns the multiplication table complexity of a radix n.
+// This is an estimate of how difficult it is to learn a radix's
+// multiplication table.
+func MTC(n uint) uint {
+	mtc := uint(0)
+	for i := uint(2); i <= n - 2; i++ {
+		mtc += n / gcd(i, n)
+	}
+	return mtc
+}
+
+func gcd(a, b uint) uint {
+	for b > 0 {
+		a, b = b, a % b
+	}
+	return a
+}