6Loops_RandomizeUniqueNumbersFrom1toN_Var2

using System;

class RandomizeUniqueNumbersFrom1toN_Var2
{
    static void Main ()
    {
        Console.Write("Enter a whole positive number, bigger from 1, for N = ");
        string numberStr = Console.ReadLine();
        uint numN = uint.Parse(numberStr);
        if (numN > 1)
        {
            Random numRandom = new Random();
            bool [] arrBool = new bool [numN + 1];
            int index = 0;
            checked
            {
                for (int i = 0; i < numN; i++)
                {
                    int numNext = numRandom.Next(1, ((int)numN + 1));
                    index = numNext;
                    if (numNext == index && arrBool[index])
                    {
                        i--;
                        continue;
                    }
                    else
                    {
                        arrBool [index] = true;
                        Console.Write("{0}  ", numNext);
                    }
                }
            }
            Console.WriteLine();
        }
        else
        {
            Console.WriteLine("Error - Invalid Number !!!");
        }
        Console.ReadLine();
    }
}