GCD of 2 strings in golang

LeetCode/ProgrammingInGo/gcd/gcdofstrings.go

@@ -0,0 +1,17 @@
+package gcd
+
+func gcd_util(a int, b int) int {
+	for b != 0 {
+		t := b
+		b = a % b
+		a = t
+	}
+	return a
+}
+func GCDofStrings(str1 string, str2 string) string {
+	null_str := ""
+	if (str1 + str2) != (str2 + str1) {
+		return null_str
+	}
+	return str1[0:gcd_util(len(str1), len(str2))]
+}

LeetCode/ProgrammingInGo/main.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"ProgrammingInGo/MinMovesToSeatEveryone"
 	"ProgrammingInGo/MergeAlternately"
+	"ProgrammingInGo/gcd"
 )
 
 func main() {
@@ -17,4 +18,9 @@ func main() {
 	fmt.Println(MergeAlternately.MergeAlternate("abc", "pqr"))
 	fmt.Println(MergeAlternately.MergeAlternate("ab", "pqrs"))
 	fmt.Println(MergeAlternately.MergeAlternate("abcd", "pq"))
+
+	// test the function
+	fmt.Println(gcd.GCDofStrings("ABCABC", "ABC"))
+	fmt.Println(gcd.GCDofStrings("ABABAB", "ABAB"))
+	fmt.Println(gcd.GCDofStrings("LEET", "CODE"))
 }