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            int[] arr = { 12, 34, 23, 2, 45, 12, 23, 34, 56, 1 };
            int del =1;
            for (int i = 0; i < arr.Length; i++)
            {
                for (int j = 0; j < i; j++)
                {
                    if (arr[i]==arr[j] && arr[i]!=0)
                    {
                        arr[i] = arr[arr.Length - del];
                        arr[arr.Length - del] = 0;
                        del++;
                        break;
                    }
                }
            }
            
            // Ausgabe in der Console
            for (int i = 0; i < arr.Length; i++)
            {
                Console.Write(arr[i] + " , ");
            }
            Console.WriteLine();
            Console.ReadLine();
        }