Error Detection (crc.java) (CN)

//Aim: Write a program for Error Detection usinng CRC.
/*For complete explanation visit: Prof. Brinda's Blog*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class crc
{
     public static void main(String args[]) throws IOException
        {
    BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
            int[] data;
            int[] div;
            int[] divisor;
            int[] rem;
            int[] crc;
            int data_bits, divisor_bits, tot_length;
          
            System.out.println("Enter number of data bits : ");
            data_bits=Integer.parseInt(br.readLine());
            data=new int[data_bits];

            System.out.println("Enter data bits : ");
            for(int i=0; i<data_bits; i++)
                data[i]=Integer.parseInt(br.readLine());

            System.out.println("Enter number of bits in divisor : ");
            divisor_bits=Integer.parseInt(br.readLine());
            divisor=new int[divisor_bits];
          
            System.out.println("Enter Divisor bits : ");
            for(int i=0; i<divisor_bits; i++)
                divisor[i]=Integer.parseInt(br.readLine());

           // Display the Data and Divisor Bits
          
            System.out.print("\n Data bits are : ");
            for(int i=0; i< data_bits; i++)
                System.out.print(data[i]);      
                   
            System.out.print("\n Divisor bits are : ");
            for(int i=0; i< divisor_bits; i++)
                System.out.print(divisor[i]);      
          
            tot_length=data_bits+divisor_bits-1;
          
            // Declaration
           
            div=new int[tot_length];
            rem=new int[tot_length];
            crc=new int[tot_length];
           
        /*------------------ CRC GENERATION-----------------------*/  
            for(int i=0;i<data.length;i++)
                div[i]=data[i];
          
            System.out.print("\n Dividend (after appending 0's) are : ");
            for(int i=0; i< div.length; i++)
                System.out.print(div[i]);      
            System.out.println();
          
            for(int j=0; j<div.length; j++)
            {
                  rem[j] = div[j];
            }
      
            rem=divide(div, divisor, rem);
          
            for(int i=0;i<div.length;i++)           //append dividend and ramainder
            {
                crc[i]=(div[i]^rem[i]);
            }
          
            System.out.println();
            System.out.println("CRC code : ");  
            for(int i=0;i<crc.length;i++)
                System.out.print(crc[i]);
              
        /*-------------------ERROR DETECTION---------------------*/  
            System.out.println();
            System.out.println("Enter CRC code of "+tot_length+" bits : ");
            for(int i=0; i<crc.length; i++)
                crc[i]=Integer.parseInt(br.readLine());
          
           
            for(int j=0; j<crc.length; j++)
            {
                  rem[j] = crc[j];
            }
      
            rem=divide(crc, divisor, rem);
          
            for(int i=0; i< rem.length; i++)
            {
                if(rem[i]!=0)
                {
                    System.out.println("Error");
                    break;
                }
                if(i==rem.length-1)
                    System.out.println("No Error");
            }
          
        }
      
        static int[] divide(int div[],int divisor[], int rem[])
        {
            int cur=0;
            while(true)
            {
                for(int i=0;i<divisor.length;i++)
                    rem[cur+i]=(rem[cur+i]^divisor[i]);
              
                while(rem[cur]==0 && cur!=rem.length-1)
                    cur++;
      
                if((rem.length-cur)<divisor.length)
                    break;
            }
            return rem;
        }
}



Output

CRC WITH ERROR 
Enter number of data bits :
5
Enter data bits :
1
1
0
0
1
Enter number of bits in divisor :
3
Enter Divisor bits :
1
1
0

 Data bits are : 11001
 Divisor bits are : 110
 Dividend (after appending 0's) are : 1100100

CRC code :
1100110
Enter CRC code of 7 bits :
1
0
0
0
1
1
0
Error

CRC WITHOUT  ERROR
Enter number of data bits :
5
Enter data bits :
1
1
0
0
1
Enter number of bits in divisor :
3
Enter Divisor bits :
1
1
0

 Data bits are : 11001
 Divisor bits are : 110
 Dividend (after appending 0's) are : 1100100

CRC code :
1100110
Enter CRC code of 7 bits :
1
1
0
0
1
1
0
No Error