public static int Range(this ZergRandom rand, int min, int max)
{
if (max <= min)
{
return(min);
}
return(min + rand.Next() % (max - min));
}
public static T RandomElement <T>(this ICollection <T> list, ZergRandom random)
{
if (list.Count < 1)
{
return(default(T));
}
return(list.ElementAt(random.Next(0, list.Count)));
}
// max is exclusive index max, count is number of random indexes returned
public static int[] RandomNonoverlappedIndices(int max, int count, ZergRandom random)
{
if (max < count)
{
int[] r = new int[max];
for (int i = 0; i < max; i++)
{
r[i] = i;
}
return(r);
}
int[] result = new int[count];
var range = Enumerable.Range(0, max).ToList();
for (int i = 0; i < count; ++i)
{
int randIndex = random.Next(0, max - i);
int rand = range[randIndex];
result[i] = rand;
range[randIndex] = range[max - i - 1];
}
return(result);
}