From 056e4b4df053dd0a8ecb1ef2f922158626f7c6b6 Mon Sep 17 00:00:00 2001
From: Ture Bentzin <ture.bentzin@alumni.fh-aachen.de>
Date: Thu, 20 Nov 2025 17:13:19 +0000
Subject: [PATCH] update: add usage

---
 Sort.java | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Sort.java b/Sort.java
index b7aa726..517d141 100644
--- a/Sort.java
+++ b/Sort.java
@@ -29,6 +29,12 @@ public class Sort {
   }
 
   public static void main(String[] args) {
+    if (args.length == 0) {
+      System.err.println("Usage: <number>...");
+      System.exit(1);
+      return;
+    }
+
     int[] input = Arrays.stream(args).mapToInt(Integer::parseInt).toArray();
     System.out.println("Input:  " + Arrays.toString(input));
     System.out.println("Output: " + Arrays.toString(selectionSort1(input)));