if the number is not prime how calculate divide number

Donovan IT

hello all i have this code

int count = 0;

int z=0;

int a = int.Parse(textBox1.Text);

for (int i = 1; i <= a; i++)

{

if (a % i == 0)

count++;

for (int j = 1; j <= a; j++)

{

if (i * j == a)

z = j*i;

}

if (count > 2)

MessageBox.Show("Not Prime " + z);

else

MessageBox.Show("Prime");

now i want to know if the number is not prime so what number can divide into .... thanks for the help

3 Replies

Know the answer? Post it — somebody with the same question will find it here.

Vulpes11y ago
Accepted answer
If you want to store all divisors - rather than just the first - for a non-prime number, then you'll need to store them in a list:

int a = int.Parse(textBox1.Text);

List divisors = new List();

for (int i = 2; i < a; i++)
{
if (a % i == 0) divisors.Add(i);
}

if (a < 2)
MessageBox.Show("Not Prime, less than 2");
else if (divisors.Count > 0)
{
string z = String.Join("\r\n", divisors);
MessageBox.Show("Not Prime, divides by the following :\r\n\r\n" + z);
}
else
MessageBox.Show("Prime");
Donovan IT11y ago
thanks for your reply , i try this but it has a problem lets say we give 8 for example , 8 is divide by 2 and 4 , but this program tells us just one number say 8 is divide by 2 only so what about the other number !!!
Vulpes11y ago
Try this:

int z = 0;

int a = int.Parse(textBox1.Text);

for (int i = 2; i < a; i++)
{
if (a % i == 0)
{
z = i;
break;
}
}

if (a < 2)
MessageBox.Show("Not Prime, less than 2");
else if (z > 0)
MessageBox.Show("Not Prime, divides by " + z);
else
MessageBox.Show("Prime");