1 files changed, 38 insertions, 0 deletions
diff --git a/lib/util/lcp.go b/lib/util/lcp.go
new file mode 100644
index 0000000..2e2e690
--- /dev/null
+++ b/lib/util/lcp.go
@@ -0,0 +1,38 @@
+// Licensed under the GNU Free Documentation License 1.2
+// https://www.gnu.org/licenses/old-licenses/fdl-1.2.en.html
+//
+// Source: https://rosettacode.org/wiki/Longest_common_prefix#Go
+
+package util
+
+func LongestCommonPrefix(list []string) string {
+	// Special cases first
+	switch len(list) {
+	case 0:
+		return ""
+	case 1:
+		return list[0]
+	}
+
+	// LCP of min and max (lexigraphically)
+	// is the LCP of the whole set.
+	min, max := list[0], list[0]
+	for _, s := range list[1:] {
+		switch {
+		case s < min:
+			min = s
+		case s > max:
+			max = s
+		}
+	}
+
+	for i := 0; i < len(min) && i < len(max); i++ {
+		if min[i] != max[i] {
+			return min[:i]
+		}
+	}
+
+	// In the case where lengths are not equal but all bytes
+	// are equal, min is the answer ("foo" < "foobar").
+	return min
+}