Prime Number Formula

Question

I am trying to write a prime number function in C# and I am wondering if the follow code will work. It \"appears\" to work with the first 50 numbers or so. I just want to ma

Answer 1

This is a simple code for find prime number depend on your input.

  static void Main(string[] args)
    {
        String input = Console.ReadLine();
        long num = Convert.ToInt32(input);
        long a, b, c;
        c = 2;
        for(long i=3; i<=num; i++){
            b = 0;
            for (long j = 2; j < i ; j++) {
                a = i % j;
                if (a != 0) {
                    b = b+1;
                }
                else {
                    break;
                }
            }

            if(b == i-2){
                Console.WriteLine("{0}",i);
            }
        }
        Console.ReadLine();
    }