Exception Errors with double Transposition program

**mdunn40** · 02-07-2016, 05:17 PM

This program prompts a user to choose encrypt, decrypt options. For the encrypt option the user enters a plain text message followed by the number of rows and number of columns then is prompted to enter a row key and column key and then the encypted text is suppose to be printed out . The decrypt option is suppose to do vice-versa. I need my row key be like for example: 3,5,1,4,2 and my column key to be 1,3,2 if the matrix row size is 5 and the column is 3. I am getting exceptions errors in this code and I am stuck and not sure what direction to proceed. Any help would be appreciated, Thanks!

Java Code:

import java.io.*;
import java.util.*;
class NewDoubleTransposition
{
	public static void main(String args[])
	{
		NewEncryptAndDecrypt ned=new NewEncryptAndDecrypt();
		ned.input();
	}
}
class NewEncryptAndDecrypt
{
	Scanner sc=new Scanner(System.in);
	void input()
	{
		int ch;
		do
		{
			System.out.println("\n\t\t*****ENTER*****");
			System.out.println("\t1.Encrypt");
			System.out.println("\t2.Decrypt");
			System.out.println("\t0.Exit");
			ch=sc.nextInt();
			switch(ch)	
			{
				case 1:
				{
					encrypt();
					break;
				}
				case 2:
				{
					decrypt();
					break;
				}
			}
		}while(ch!=0);
	}
	void encrypt()
	{
		String ip,t;
		char text[][],enc[][];
		int key,i,j,row[],col[],r,c;
		int k=0,m,n;
		System.out.print("Enter The Plain Text ");
		ip=sc.next();
		t=sc.nextLine();
		System.out.print("Enter The Number Of Rows ");
		r=sc.nextInt();
		System.out.print("Enter The Number Of Columns ");
		c=sc.nextInt();
		text=new char[r][c];
		enc=new char[r][c];
		row=new int[r];
		col=new int[c];
		for(i=0;i<r;i++)
		{
			for(j=0;j<c;j++)
			{
				text[i][j]=ip.charAt(k);
				k++;
			}
		}
		System.out.println("Enter The Row Key ");
		for(i=0;i<r;i++)
			row[i]=(sc.nextInt()-1);
		System.out.println("Enter The Column Key ");
		for(i=0;i<c;i++)
			col[i]=(sc.nextInt()-1);
		k=0;
		System.out.print("The Cipher Text Is ");
		for(i=0;i<r;i++)
		{
			m=row[i];
			for(j=0;j<c;j++)
			{
				n=col[j];
				enc[i][j]=text[m][n];
				System.out.print(""+Character.toUpperCase(enc[i][j]));
			}
		}
	}
	void decrypt()
	{
		String ip,t;
		char text[][],enc[][];
		int key,i,j,row[],col[],r,c;
		int k=0,m,n;
		System.out.print("Enter The Cipher Text ");
		ip=sc.next();
		t=sc.nextLine();
		System.out.print("Enter The Number Of Rows ");
		r=sc.nextInt();
		System.out.print("Enter The Number Of Columns ");
		c=sc.nextInt();
		text=new char[r][c];
		enc=new char[r][c];
		row=new int[r];
		col=new int[c];
		for(i=0;i<r;i++)
		{
			for(j=0;j<c;j++)
			{
				text[i][j]=ip.charAt(k);
				k++;
			}
		}
		System.out.println("Enter The Row Key ");
		for(i=0;i<r;i++)
			row[i]=(sc.nextInt()-1);
		System.out.println("Enter The Column Key ");
		for(i=0;i<c;i++)
			col[i]=(sc.nextInt()-1);
		k=0;
		for(i=0;i<r;i++)
		{
			m=row[i];
			for(j=0;j<c;j++)
			{
				n=col[j];
				enc[m][n]=text[i][j];
			}
		}
		System.out.print("The Retrieved Plain Text Is ");
		for(i=0;i<r;i++)
		{
			for(j=0;j<c;j++)
			{
				System.out.print(""+Character.toLowerCase(enc[i][j]));
			}
		}
	}	
}