initial commit

util.go

@@ -0,0 +1,19 @@
+package lottery
+
+import (
+	"math/rand"
+	"sort"
+)
+
+// drawUnique returns count unique numbers in the range [1, max].
+// It uses the rand.Perm function to generate a random permutation of numbers and selects the first count numbers from it.
+// The result is sorted before being returned.
+func drawUnique(count, max int) []int {
+	perm := rand.Perm(max)
+	result := make([]int, count)
+	for i := range result {
+		result[i] = perm[i] + 1
+	}
+	sort.Ints(result)
+	return result
+}