/// <summary>
/// Creates a copy of a list with the items in random order.
/// </summary>
/// <param name="list">
/// The list to copy.
/// </param>
/// <param name="randNumGen">
/// An object that generates random numbers.
/// </param>
/// <returns>
/// A copy of the list with its items shuffled (their order in the
/// list is random).
/// </returns>
public static Generic.IList <T> Shuffle <T>(Generic.IList <T> list,
System.Random randomNumGen)
{
if (list == null)
{
return(null);
}
Require.ArgumentNotNull(randomNumGen);
// List of item indexes.
Generic.List <int> indexes = new Generic.List <int>(list.Count);
for (int i = 0; i < list.Count; ++i)
{
indexes.Add(i);
}
Generic.List <T> shuffledList = new Generic.List <T>(list.Count);
while (indexes.Count > 0)
{
// Randomly pick a remaining item in the list
int indexOfIndex = randomNumGen.Next(indexes.Count);
int index = indexes[indexOfIndex];
indexes.RemoveAt(indexOfIndex);
shuffledList.Add(list[index]);
}
return(shuffledList);
}
