kgaughan · December 8, 2021 17:04 · Dec 8, 2021
diff --git a/permute.go b/permute.go
@@ -0,0 +1,27 @@
+package permute
+
+func fact(n int) int {
+	result := 1
+	for i := 1; i <= n; i++ {
+		result *= i
+	}
+	return result
+}
+
+func permute(chars string) []string {
+	result := make([]string, 0, fact(len(chars)))
+	generate(&result, []rune(chars), 0, len(chars)-1)
+	return result
+}
+
+func generate(result *[]string, acc []rune, left, right int) {
+	if left == right {
+		*result = append(*result, string(acc))
+	} else {
+		for i := left; i <= right; i++ {
+			acc[left], acc[i] = acc[i], acc[left]
+			generate(result, acc, left+1, right)
+			acc[left], acc[i] = acc[i], acc[left]
+		}
+	}
+}