You are given a function ‘secret()’ that accepts a single integer parameter and returns an integer. In your favorite programming language, write a program that takes one argument (a number) and determines if the secret() function is additive [secret(x+y) = secret(x) + secret(y)], for all values x and y, where x and y are prime numbers less than the 100.

public static bool isPrime(int number)
{

for (int i = 2; i < number; i++)
{
if (number % i == 0)
{
return false;
}
}

return true;
}

public int secret(int x)
{
if ((x < 100) && isPrime(x))
return (x);
else return (0);
}

private void button1_Click(object sender, EventArgs e)
{
int val1=secret(Convert.ToInt32(textBox1.Text));
int val2 = secret(Convert.ToInt32(textBox2.Text));

if (val1 == 0 || val2 == 0)
{
label1.Text = "Prime number and between 0 to 100 please";
return;
}

int final = Convert.ToInt32(textBox1.Text) + Convert.ToInt32(textBox2.Text);
int val3 = secret(final);
if (val3 == val1 + val2)
{
label1.Text = "Perfect!!!";
}

}

Am I missing something here?

Is this sort-of puzzle question or just simple programming one? If the latter then batman's response is on the money. It first adds two numbers entered and it then checks whether the sum is the sum of the two numbers; ofcourse the answer will be always "Perffect!!!", unless some one doesn't enter the number correctly.

My guess is that there is something more to the question. Definition of additive is too simple, did you mean something else?

Kiddo bro, this is not puzzle. Conpletely coding . This is copy paste from one of the interview i took some time back.

Is there some relation between "one argument (a number)" and (x, y) (or 100)?