Java program to perform binary addition,subtraction and modulus.

Question

i am a newbie to java and require ur urgent help plzzzz.
i wanna perform binary addition,subtraction and modulus operation between two numbers of 512 bit without using java functions i.e by simple logics of control statements.i need to convert two 512 bit numbers passed as string into binary form, and then perform addition,subtraction and modulus operations on these two binary numbers and finally dipaly the result in decimal format.
i think we may use full adder binary logic in this!!!
please send me the java coding for these three operations as urgent as possible on my email.
i would be highly obliged.
thanks.
sheetal.

Answer 1

i have managed to make this code myself but i wanna learn the basics...so plz help me guyz...
this is the code:
package bytearrayopeations;
import java.math.BigInteger;
* @author sheetalb
public class binaryadding {
public static void main(String[] args) {
BigInteger a = new BigInteger("123456");
BigInteger b = new BigInteger("5121");
String bb1 = a.toString(2);
String bb2 = b.toString(2);
String ss1 = null;
String ss2 = null;
String result = "";
String carry="0";
System.out.println("first value=" +bb1);
System.out.println("second value=" +bb2);
int k=bb1.length();
int h=bb2.length();
System.out.println("length 1="+ k);
System.out.println("length 2=" +h);
int p=h-k;
//System.out.println("difference=" +p);
int q=k-h;
//System.out.println("difference 2=" +q);
if(h==k)
else if(h>k)
for(int i=0;i<p;i++)
bb1="0"+bb1;
System.out.println("new value of first=" +bb1);   
else if(h<k)
for(int i=0;i<q;i++)
bb2="0"+bb2;
System.out.println("new value of second=" +bb2);
StringBuffer sb1=new StringBuffer(bb1);
     StringBuffer sb2=new StringBuffer(bb2);
bb1=sb1.reverse().toString();
     bb2=sb2.reverse().toString();
//System.out.println("rev. buffer1=" +bb1);
//System.out.println("rev. buffer2=" +bb2);
for(int i=0;i<bb1.length();i++)
ss1=bb1.substring(i,i+1);
ss2=bb2.substring(i,i+1);
System.out.println("value1=" + ss1 + " " + "value2=" + ss2);
if (ss1.equals("0") && ss2.equals("0"))
if (carry.equals("0"))
result+="0";
else
result+="1";
else if (ss1.equals("1") && ss2.equals("1"))
if (carry.equals("0"))
result+="0";
          carry="1";
          else
               result+="1";
               carry="1";
else if (ss1.equals("0") && ss2.equals("1"))
if (carry.equals("0"))
     result+="1";
               carry="0";
                    else
                    result+="0";
carry="1";
else if (ss1.equals("1") && ss2.equals("0"))
if (carry.equals("0"))
result+="1";
carry="0";
               else
result+="0";
carry="1";
System.out.println("sum=" result " " + "carry" + carry);
result+=carry;
StringBuffer sb3=new StringBuffer(result);
result=sb3.reverse().toString();
System.out.println("result is " +result); 
System.out.println("Binary = "+ result + ", Decimal = "+Integer.parseInt(result,2));
plz reply nw...