initial commit

backend/util/common/random.go

@@ -0,0 +1,13 @@
+package common
+
+import "math/rand"
+
+var allSeq [62]rune
+
+func Random(n int) string {
+	runes := make([]rune, n)
+	for i := 0; i < n; i++ {
+		runes[i] = allSeq[rand.Intn(len(allSeq))]
+	}
+	return string(runes)
+}