Binary Addition with the Carry Bit

Question

This is probably going to be a stupid question but I'm stuck on it and hopefully someone here can help me. I'm to take 2 integers provided by the command line and then convert them to 32bit binary numbers. Then numbers are added. The result should come out to something like this.
00000000000000000000000000011110 carry
00000000000000000000000000011110 a - first operand
00000000000000000000000000110010 b - second operand
00000000000000000000000001010000 a+b - result
My problem is I can't figure out how to get the carry bit to interact with the other operands. Here's what I have so far. Sorry if it gets messed up the formatting.
import java.io.*;
public class BitAdder {
     public static void main(String[] args) {
     if (args.length != 2) {
          System.out.println("SYNTAX: java BitAdder Operand1 Operand2");
          System.exit(1);
     int first = Integer.parseInt(args[0]);
     int second = Integer.parseInt(args[1]);
     int result;
     int carry;
     int one = 1;
     int zero = 0;
     //sFirst and sSecond are String versions of the binary numbers. first and second are
     //int versions of those same numbers.
     String sFirst = Integer.toBinaryString(first);
     String sSecond = Integer.toBinaryString(second);
     int firstLength = sFirst.length();
     int secondLength = sSecond.length();
     first = Integer.parseInt(sFirst);
     second = Integer.parseInt(sSecond);
     int fUnused = 32 - firstLength;
     int sUnused = 32 - secondLength;
     for (int i = 0; i < fUnused; i++) {
          sFirst = "0" + sFirst;
     for (int i = 0; i < sUnused; i++) {
          sSecond = "0" + sSecond;
     BufferedReader fRead;
     BufferedReader sRead;
     fRead = new BufferedReader(new StringReader(sFirst));
     sRead = new BufferedReader(new StringReader(sSecond));
     try {
          fRead.mark(35);
          sRead.mark(35);
          //for whatever reason the Reader sees 0's as 48 and 1's as 49
          for (int i = 0; i < 32; i++) {
               int carFir = fRead.read();
               int carSec = sRead.read();
               //both are 0
               if( carFir == 48 && carSec == 48 ) {
                    System.out.print("0");
               // one is 1, the other 0
               else if (carFir == 49 && carSec == 48 || carFir == 48 && carSec == 49) {
                    System.out.print("0");
               //both are 1's
               else if (carFir == 49 && carSec == 49) {
                    System.out.print("1");
               //something has gone wrong and the results aren't 1's and 0's anymore
               else {
                    System.out.print("wtf");
          System.out.print(" carry");
          fRead.reset();
          sRead.reset();
          System.out.println("");
     catch (IOException ioe) {
          System.out.println("Exception " + ioe);
     System.out.println(" " + sFirst + " a - first operand");
     System.out.println(" " + sSecond + " b - second operand");
     try {
          System.out.print(" ");
          //for whatever reason the Reader sees 0's as 48 and 1's as 49
          for (int i = 0; i < 32; i++) {
               int firstIn = fRead.read();
               int secondIn = sRead.read();
               //both are 0
               if( firstIn == 48 && secondIn == 48 ) {
                    System.out.print("0");
               // one is 1, the other 0
               else if (firstIn == 49 && secondIn == 48 || firstIn == 48 && secondIn == 49) {
                    System.out.print("1");
               //both are 1's
               else if (firstIn == 49 && secondIn == 49) {
                    System.out.print("0");
               //something has gone wrong and the results aren't 1's and 0's anymore
               else {
                    System.out.print("wtf");
          System.out.print(" a+b - result");
     catch (IOException ioe) {
          System.out.println("Exception " + ioe);
Any help would be greatly appreciated. Thanks in advance.

Answer 1

In your example the second bit in carry should be 0. You get 48='0' and 49='1' because you read ASCII characters.
int carry = 0;
for (int i = 0; i < 32; i++) {
   int first = 0;
   int second = 0;
   int firstIn = fRead.read();
   if (firstIn = 49)
      first = 1;
   int secondIn = sRead.read();
   if (secondIn = 49)
      second = 1;
   int add = first + second + carry;
      //both are 0
   if(add == 0) {
      carry = 0;
      System.out.print("0");
      // one is 1, the other 0
    else if (add == 1) {
      carry = 0;
       System.out.print("1");
       //both are 1's
    else if (add == 2) {
       carry = 1;
       System.out.print("0");
       //both are 1's and carry is 1
    else if (add == 3) {
       carry = 1;
       System.out.print("1");