/*
 * T01n02.java -- Demonstrates twos-complement integer overflow.  We start
 * with a large integer value, and increase it by one until doing so
 * causes the sign bit to flip, making the result very negative.
 */

import java.io.*;

public class T01n02
{
    final static int BITS_PER_INT = 32;    // Java ints always have 32 bits

    public static void main (String[] args)
    {
        int intValue = 2147483645;         // 2^31 - 3

        bitPrint(intValue); System.out.println(" = " + intValue++);
        bitPrint(intValue); System.out.println(" = " + intValue++);
        bitPrint(intValue); System.out.println(" = " + intValue++);
        bitPrint(intValue); System.out.println(" = " + intValue++);
    }

        /*
         * bitPrint(value) -- Displays an int in twos-complement binary form.
         * This method uses very little that we've covered in class to this
         * point, so don't worry about how it works!
         */

    public static void bitPrint (int value)
    {
        int mask = 1 << (BITS_PER_INT-1);

        for (int i=1; i <= BITS_PER_INT; i++) {
            System.out.print(((value & mask) == 0) ? "0" : "1");
            value <<= 1;
        }
    }
}