Intersection of two int array in C#

Question

I am trying to find the intersection of two int array . I am using this code :

  public int[] Find_Common_Elements(int[] p1, int[] p2)
    {
        int count = 0;
        for (int i = 0; i < p1.Length; i++)
        {
            for (int j = 0; j < p2.Length; j++)
            {
                if (p1[i] == p2[j])
                {
                    count++;
                    break;
                }
            }
        }

        int[] result = new int[count];
        count = 0;
        for (int i = 0; i < p1.Length; i++)
        {
            for (int j = 0; j < p2.Length; j++)
            {
                if (p1[i] == p2[j])
                {
                    result[count++] = p1[i];
                    break;
                }
            }
        }

        return result;
    }

    public int[] BubbleSort(int[] numarray)
    {
        int max = numarray.Length;
        for (int i = 1; i < max; i++)
        {
            for (int j = 0; j < max - i; j++)
            {

                if (numarray[j] > numarray[j + 1])
                {
                    int temp = numarray[j];
                    numarray[j] = numarray[j + 1];
                    numarray[j + 1] = temp;
                }
            }
        }
        return numarray;
    }

    public int[] Find_Unique_Elements(int[] numarray)
    {
        BubbleSort(numarray);
        int element = numarray[0];
        int count = 1;
        for (int i = 1; i < numarray.Length; i++)
        {
            if (element == numarray[i])
                continue;
            else
            {
                element = numarray[i];
                count++;
            }
        }

        int[] result = new int[count];

        count = 0;
        element = numarray[0];
        result[count++] = element;
        for (int i = 1; i < numarray.Length; i++)
        {
            if (element == numarray[i])
                continue;
            else
            {
                element = numarray[i];
                result[count++] = element;
            }
        }
        return result;
    }

    public void Result()
    {
        int[] array1 = new int[] { 10, 20, 30, 40, 50, 60, 70, 80, 90, 100,
             95, 85, 75, 65, 55, 45, 35, 25, 15, 05,
             10, 15, 20, 25, 30, 35, 40, 45, 50, 55
        };

        int[] array2 = new int[] { 15, 25, 35, 45, 55,
             12, 22, 32, 43, 52,
             15, 25, 35, 45, 55
        };

        int[] p1 = Find_Unique_Elements(array1);
        int[] p2 = Find_Unique_Elements(array2);
        int[] result = Find_Common_Elements(array1, array2);

        for (int i = 0; i < p1.Length; i++)
            textBox1.Text += "\n" + p1[i].ToString();
        for (int i = 0; i < p2.Length; i++)
            textBox2.Text += "\n" + p2[i].ToString();
        for (int i = 0; i < result.Length; i++)
            textBox3.Text += "\n"+result[i].ToString();
        }








    private void button1_Click(object sender, RoutedEventArgs e)
    {
        Result();
    }

But the problem is that, the result obtained is 15 15 25 25 35 35 45 45 55 55 , and i want 15 25 35 45 55. what is the problem with this code ? Thanks for any help

Answer 1

You can use the built-in Linq Intersect extension method for this:

using System.Linq; // Make sure you include this line

public int[] Find_Common_Elements(int[] p1, int[] p2)
{
    return p1.Intersect(p2).ToArray();
}