Prime generator in java

Question

I wrote this program for generating prime numbers between two values. It's working perfectly for integer values. I tried to make it work for long integer values but the program exits without any processing whenever long integer values are input. Please help me find problem with the code
The code goes as follows.

public class Prime_generator
{
    public static void main(String[] args) {
        Scanner src = new Scanner(System.in);
        Prime_generator obj = new Prime_generator();
        int t, i, a;

        t = src.nextInt();
        if (t > 10)
            System.exit(0);
        long a1[] = new long[t];
        long a2[] = new long[t];

        for (i = 0; i < t; i++) {
            a1[i] = src.nextLong();
            a2[i] = src.nextLong();  
        }
        for (a = 0; a < t; a++)
        {

            if (a1[a] >= 1 && a1[a] <= 1000000000 && a2[a] >= 1 && a2[a] <= 1000000000 && a2[a] - a1[a] <= 100000 && a1[a] <= a2[a])
                obj.prime(a1[a], a2[a]);
            else
                System.exit(0);
        }

    }
    void prime(long m, long n)
    {
        long j,k;
        long c=0L;
        for(j=m;j<=n;j++)
        {
            c=0L;
            for(k=2;k<j/2;k++)
            {
                if((long)j%k==0L)
                c++;

            }
            if(c==0L)
                System.out.println(j);
        }
        System.out.println(" ");

    }
}

Probably integer overflow – Gurwinder Singh Dec 17 '16 at 07:59 — Gurwinder Singh, Dec 17 '16 at 07:59

score 0 · Accepted Answer · answered Dec 17 '16 at 08:21

0

it's the size limit in the if statment. you should use a long limit, you are using an integer there. this is an example to if statment with long

if (a1[a] >= 1 && a1[a] <= 1000000000000000l && a2[a] >= 1 && a2[a] <= 1000000000000000l && a2[a] - a1[a] <= 1000000000000000l && a1[a] <= a2[a])

answered Dec 17 '16 at 08:21

Ran Koretzki

464
3
15

Your welcome. don't forgat to mark the answer as correct :) – Ran Koretzki Dec 17 '16 at 15:44

Prime generator in java

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