java integer not working as expected

Question

Here is my code this should output (8477559501395327) but it is giving(2084842641) whats the problem here. I tried long instead of int but it gives some different answer

    int counter = 0;
    int counter2 =0;
    int k=203903;
    int result=0;
    int countequalk =0;
    int i=0;

   while(true){


        if( i % 2 != 0){
            counter++;
            if(counter<k){
                counter2=counter2+counter;
            }
            //System.out.println(counter+" "+i);

           if(counter>counter2&&counter<=counter2+k){

               result = result+i;
               countequalk++;
           }
           if(countequalk==k){
               break;
           }
        }
        i++;

    }

    System.out.println(result);

Don't kid yourself. 'Not working as expected': maybe; 'not working correctly', no chance. — user207421, Dec 06 '17 at 06:30

Óscar López · Answer 1 · 2017-12-06T06:22:34.120

2

The number 8477559501395327 doesn't fit into an int - which supports values up to 2^31 - 1, as specified by Integer.MAX_VALUE. try using a long instead, which has a maximum value of 2^63 - 1, as indicated by Long.MAX_VALUE. This value is greater than 8477559501395327, so it fits. For even bigger numbers, better use BigInteger.

edited Dec 06 '17 at 06:22

answered Dec 06 '17 at 06:20

Óscar López

232,561
37
312
386

Or even better, `BigInteger`. – Jus12 Dec 06 '17 at 06:21
Or long unsigned if you know you're staying in the positives. (I assume Java has unsigned ints, if not it's trivial to implement) – Max von Hippel Dec 06 '17 at 06:22
2

@MaxvonHippel nope, Java doesn't have unsigned integers. – Óscar López Dec 06 '17 at 06:23
Though guava, a common util library, does have helper methods for working with longs as unsigned. – yshavit Dec 06 '17 at 06:24
1

@MaxvonHippel And no, they are not 'trivial to implement'. – user207421 Dec 06 '17 at 06:29
@EJP I've implemented both before for homework, but considering you know more about Java, I'll assume your point is that they are difficult to implement well (that there are subtleties to doing it *right* that students such as myself likely gloss over)? – Max von Hippel Dec 06 '17 at 06:38

java integer not working as expected

1 Answers1