How to split array dynamically in unique arrays

Question

I have this mainArray (dynamically generated):

    static void Main()
{
    var n = 3;
    var k = 2;
    var a = n * k;
    var mainArray = new int[a];
    var index = 0;
    for (var i = 0; i < n; i++)
    {
        for (var j = 0; j < k; j++)
        {
            mainArray[index] = i;
            index++;
        }
    }

    //=> mainArray=[0,0,1,1,2,2]
    // How to split this array in 3 uniq arrays, like:
    //array1=[0,1]
    //array2=[1,2]
    //array3=[0,2]

    Console.WriteLine(String.Join(",", mainArray));
    Console.ReadLine();
}

mainArray=[0,0,1,1,2,2]

How to split this array in 3 uniq arrays, like:

array1=[0,1]

array2=[1,2]

array3=[0,2]

How can I do it?

[0,0] [1,1],[2,2] = not uniq; [0,1],[0,1][2,2]=not uniq; , only uniq posibility is the one from my question; — Lucian Bumb
– Lucian Bumb, Commented Mar 5, 2016 at 14:45

Ivan Gritsenko · Accepted Answer · 2016-03-05 15:01:23Z

1

So initially you have a set of n * k items of n different values where each value is repeated k times. And you want to arrange those n * k items into k sets in such a way that each value in the resulting sets is unique.

You can do it in the following way

int[][] res = Enumerable.Range(0, n).Select(x => new int[k]).ToArray();
for(int i = 0; i < n; i++)
    for(int j = 0; j < k; j++)
        res[i][j] = (i + j) % n;

edited Mar 5, 2016 at 15:01

answered Mar 5, 2016 at 14:55

Ivan Gritsenko

4,2262 gold badges23 silver badges35 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Patrick Bell · Accepted Answer · 2016-03-05 14:53:56Z

Do you mean to say that all of the arrays have to have different numbers in each array, or that each array must be unique from the others?

If you want to just make arrays with unique numbers, try the following. I'm sure there is a better solution, but I'm fairly certain this may work for your situation.

public static int[][] splitUnique(int[] input, int length)
    {
        if (input.Length % length != 0) throw new Exception("Length cannot yield full arrays of length " + length);
        List<int> numbers = new List<int>(input);
        int[][] data = new int[input.Length / length][];
        int dataIndex = 0;
        while (numbers.Count != 0)
        {
            int[] temp = new int[length];
            int tempIndex = 0;
            foreach (int num in numbers)
            {
                if (!temp.Contains(num))
                {
                    temp[tempIndex] = num;
                    tempIndex++;
                }
                if (tempIndex >= length)
                {
                    break;
                }
            }
            foreach (int num in temp)
            {
                numbers.Remove(num);
            }
            data[dataIndex] = temp;
            dataIndex++;
        }
        return data;
    }

Collectives™ on Stack Overflow

How to split array dynamically in unique arrays

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related