Generating random, unique values C#
I thought that I was after an algorithm that shuffled an array of characters but in fact I was after something else.
However, I did find this algorithm and discussion around shuffling an array of characters and thought that it was worth making note of.
The following is an implementation of the Fisher-Yates Shuffle (aka the Knuth Shuffle).
using System;
using System.Collections.Generic;
namespace ConsoleApplication2
{
static class Program
{
static void Main(string[] args)
{
Shuffler shuffler = new Shuffler();
List<int> list = new List<int>{ 1, 2, 3, 4, 5, 6, 7, 8, 9 };
shuffler.Shuffle(list);
foreach (int value in list)
{
Console.WriteLine(value);
}
}
}
/// <summary>Used to shuffle collections.</summary>
public class Shuffler
{
/// <summary>Creates the shuffler with a <see cref="MersenneTwister"/> as the random number generator.</summary>
public Shuffler()
{
_rng = new Random();
}
/// <summary>Shuffles the specified array.</summary>
/// <typeparam name="T">The type of the array elements.</typeparam>
/// <param name="array">The array to shuffle.</param>
public void Shuffle<T>(IList<T> array)
{
for (int n = array.Count; n > 1; )
{
int k = _rng.Next(n);
--n;
T temp = array[n];
array[n] = array[k];
array[k] = temp;
}
}
private System.Random _rng;
}
}
Reference: StackOverflow