Error in arrays(binary multiplication)

Question

import java.io.*;
class binaryMultiply1
private static int length;
private static int arr [], brr [];
public static int recurrsive (int n, int arr [], int brr [])
int mid = 0; //mid = n/2
int arrH [] = new int [n * 2]; //the first half of array (arr)
int arrL [] = new int [n * 2]; //the second half of array(arr)
int brrH [] = new int [n * 2]; //first half of array( brr)
int brrL [] = new int [n * 2]; //the second half of array(brr)
int x; //arrH+brrH
int y; //arrL+brrL
int z; //(arrH+arrL)(brrH+brrL)
int aofsum [] = new int [n * 2]; //sum of a
int bofsum [] = new int [n * 2]; // sum of b
int k = (int) ((Math.pow (2, n)) - (Math.pow (2, n / 2))) * x;
k += (int) ((Math.pow (2, n)) - (Math.pow (2, n / 2))) * y;
k += z;
return k;
//int m1[] = new int [n * 2]; //
// int m2[] = new int [n * 2];
// int result [] = new int [n * 2];
int c1 = 0; //carry of a
int c2 = 0; // carry of b
for (int i = 0 ; i < n * 2 ; i++)
arrH = 0;
arrL [i] = 0;
brrH [i] = 0;
brrL [i] = 0;
aofsum [i] = 0;
bofsum [i] = 0;
//m1 [i] = 0;
// m2 [i] = 0;
if (n == 1)
k = arrH [0] * brrH [0];
return k;
else
mid = n / 2;
for (int i = 0 ; i < mid ; i++)
arrH [i] = arr [i];
brrH [i] = brr [i];
for (int j = 0, i = mid ; i < n ; i++, j++)
arrL [j] = arr [i];
brrL [j] = brr [i];
x = recurrsive (mid, arrL, brrL);
y = recurrsive (mid, arrH, brrH);
int i = 0;
for (i = mid - 1 ; i > 0 ; i--)
aofsum [i] = arrH [i] + arrL [i] + c1;
bofsum [i] = brrH [i] + brrL [i] + c2;
//if (i != mid - 1)
if (aofsum [i] == 2)
aofsum [i] = 0;
c1 = 1;
else if (aofsum [i] == 3)
aofsum [i] = 1;
c1 = 1;
else
c1 = 0;
if (bofsum [i] == 2)
bofsum [i] = 0;
c2 = 1;
else if (bofsum [i] == 3)
bofsum [i] = 1;
c2 = 1;
else
c2 = 0;
aofsum [0] = arrH [0] + arrL [0] + c1;
bofsum [0] = brrH [0] + brrL [0] + c2;
z = recurrsive (mid, aofsum, bofsum);
public static void main (String args [])
int length;
System.out.println ("Enter bit length:");
length = input.getInt ();
arr = new int [length];
brr = new int [length];
//result = new int [2 * length];
System.out.println ("Enter first binary no:");
for (int i = 0 ; i < length ; i++)
arr [i] = input.getInt ();
System.out.println ("Enter second binary no:");
for (int i = 0 ; i < length ; i++)
brr [i] = input.getInt ();
int output = recurrsive(length,arr[],brr[]);
System.out.println ("output=" + output);
int c [];
c = new int [2 * length];
for (int i = 0 ; i < 2 * length ; i++)
c [i] = 0;
int i = 2 * length - 1;
while (output > 0)
if (output % 2 != 0)
c [i] = 1;
output /= 2;
i--;
for (i = 0 ; i < 2 * length ; i++)
System.out.print (c [i]);
// class to take input from the console
import java.io.*;
class input
static BufferedReader stndin;
static String line;
public static int getInt () // method reads integer values
int i=0;
stndin = new BufferedReader (new InputStreamReader (System.in));
System.out.flush ();
try
if ((line = stndin.readLine ()) != null)
i = Integer.valueOf (line).intValue ();
catch (Exception e)
System.out.println ("Error in the input");
return i; //returns the integer form the keyboard

Answer 1

1) please use the code tags
2) please ask a question3) Do also explain what your program is supposed to do, and how you think it works, and why/how it fails.
/Kaj