Flood fill recursive algorithm

Question

I\'m trying to make an algorithm that could fill an int array in c#. Basically, as the fill tool in MS Paint, I have a color and if I choose (x,y) coordinates in the array,

Answer 1

How about using a stack/queue to manage the remaining work?

public void Fill(int[,] array, int x, int y, int newInt)
{
    int initial = array[x,y];

    Queue> queue = new Queue>();
    queue.Push(new Tuple(x, y));

    while (queue.Any())
    {
        Tuple point = queue.Dequeue();

        if (array[point.Value1, point.Value2] != initial)
            continue;

        array[point.Value1, point.Value2] = newInt;

        EnqueueIfMatches(array, queue, point.Value1 - 1, point.Value2, initial);
        EnqueueIfMatches(array, queue, point.Value1 + 1, point.Value2, initial);
        EnqueueIfMatches(array, queue, point.Value1, point.Value2 - 1, initial);
        EnqueueIfMatches(array, queue, point.Value1, point.Value2 + 1, initial);        
    }
}

private void EnqueueIfMatches(int[,] array, Queue> queue, int x, int y, int initial)
{
    if (x < 0 || x >= array.GetLength(0) || y < 0 || y >= array.GetLength(1))
        return;

    if (array[x, y] == initial)
       queue.Enqueue(new Tuple(x, y));
}