Question

I’m trying to make a Integer (int) array with random numbers NOT growing.
For example: 3 10 5 9 20
But NOT: 3 5 9 10 20 (because they just grow)

I’m using Random class with this code (but I always get a growing list like in the second example):

int[] array1 = new int[5];
Random random_istance = new Random();
for (int i=0;i<5;i++)
{
 array1[i] = random.Next(0,999999);
}

I also tried with a code like (I know it is horrible programming) :

int[] array1 = new int[5];
Random random_istance = new Random();
for (int i=0;i<5;i++)
{
 random = new Random(x-y*z); // re-instantation
 array1[i] = random.Next(0,999999);    // x,y and z are variable defined outside
}

(*) My final goal is to get an array of random int between 0 and 999999 but some are to not to be in a sequence (because later I’m going to apply an algorithm to order the array and would not make sense to order a already-ordered array).

Moreover I have to create ANOTHER array with elements just DECREASING (so one random array , and one decreasing array).

Any idea how to salve at least first problem (*)?

Thanks in advance for any help.

Answer 1

One way to ensure that your array is not sorted from low to high is by ordering it randomly when you detect its ordered based on the value, something like:

        // while the array is sorted
        var sortedCopy = array1.ToList();
        sortedCopy.Sort();
        while (array1.SequenceEqual(sortedCopy))
        {
            Array.Sort(array1, new Comparison<int>((left, right) => random.Next(-1, 1)));
        }