6Loops_PrintUniqueRandomNumbersFrom1toN

using System;

class PrintUniqueRandomNumbersFrom1toN
{
    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();
            int[] randomNums = new int[numN];
            int numNext = 0;
            for (int i = 0; i < numN; i++)
            {
                numNext = numRandom.Next(1, ((int)numN + 1));

                for (int j = i; j >= 0; j--)
                {
                    if (randomNums[j] == numNext)
                    {
                        numNext = numRandom.Next(1, ((int)numN + 1));
                        j = i;
                    }
                }
                randomNums[i] = numNext;
            }
            foreach (var number in randomNums)
            {
                Console.Write("{0}  ", number);
            }
            Console.WriteLine();
        }
        else
        {
            Console.WriteLine("Error - Invalid Number !!!");
        }
        Console.ReadLine();
    }
}