import java.io.*;
import java.util.StringTokenizer;

class Prob1 
{
	public static void main( String [] args ) 
	{
		System.out.print( "Input File: " );
		String inputFile = UserInput.readString();
		System.out.print( "Output File: " );
		String outputFile = UserInput.readString();
		//------------------------------------
		BufferedReader rd = null;
		BufferedWriter wr = null;
		try 
		{
			rd = new BufferedReader( new FileReader( inputFile ) );
		}
		catch ( FileNotFoundException e ) 
		{
			System.out.println( "cannot open the read file: " + inputFile + "; Error: " + e );
		}
		try 
		{
			wr = new BufferedWriter( new FileWriter( outputFile ) );
		}
		catch ( IOException e ) 
		{
			System.out.println( "cannot open the write file: " + outputFile + "; Error: " + e );
		}
		//------------------------------------
		System.out.println( "THE READ FILE CONTAINS:" );
		String data = null;
		try 
		{
			while ( (data = rd.readLine()) != null ) 
			{
				System.out.println( data );
			}
		}
		catch ( IOException e ) {}
		//------------------------------------
		System.out.println( "Enter anything you want and it will be right out to the file." );
		System.out.println( "Enter \"I quit\" to exit the program." );
		try 
		{
			do 
			{
				data = UserInput.readString();
				wr.write( data );
				wr.newLine();
			} while ( !data.equalsIgnoreCase( "I quit" ) );
		}
		catch ( IOException e ) {}
		//------------------------------------
		try 
		{
			rd.close();
			wr.close();   // What would happen if this statement is commented out?
		}
		catch ( IOException e ) 
		{
			System.out.println( "Error Closing Files: " + e );
		}
	}
}

class Prob2to4 
{
	public static void main( String [] args ) 
	{
		String testString = "      \tTest    trim string!     ";
		System.out.println( "Test Triming String (own algo)" );
		System.out.println( "------------------------------" );
		String str1 = trimString_OwnAlgo_Iteratively( testString );
		System.out.println( "I/P: " + testString );
		System.out.println( "O/P: " + str1 );
		System.out.println( "\nTest Triming String (trim method)" );
		System.out.println(   "---------------------------------" );
		str1 = testString.trim();
		System.out.println( "I/P: " + testString );
		System.out.println( "O/P: " + str1 );

		testString = "      \tTest    removing white space characters!     ";
		System.out.println( "\nTest Removing Whitespaces from String (own algo)" );
		System.out.println(   "------------------------------------------------" );
		str1 = removeAllWhiteSpacesFromString_OwnAlgo_Iteratively( testString );
		System.out.println( "I/P: " + testString );
		System.out.println( "O/P: " + str1 );
		System.out.println( "\nTest Removing Whitespaces from String (use StringTokenizer)" );
		System.out.println(   "-----------------------------------------------------------" );
		str1 = removeAllWhiteSpacesFromString_StringTokenizer_Iteratively( testString );
		System.out.println( "I/P: " + testString );
		System.out.println( "O/P: " + str1 );
		System.out.println( "\nTest Removing Whitespaces from String (own algo recursively)" );
		System.out.println(   "------------------------------------------------" );
		str1 = removeAllWhiteSpacesFromString_OwnAlgo_Recursively( testString );
		System.out.println( "I/P: " + testString );
		System.out.println( "O/P: " + str1 );

	}

	public static String trimString_OwnAlgo_Iteratively( String str ) 
	{
		String outStr = "";
		// Find the first non white space at the start of string
		int startIdx = 0;
		for ( int i = 0; i < str.length(); ++i ) 
		{
			if ( str.charAt( i ) != ' ' && str.charAt( i ) != '\t' ) 
			{
				startIdx = i;
				break;
			}
		}
		// Find the first non white space at the start of string
		int endIdx = str.length() - 1;
		for ( int i = str.length()-1; i >= 0; --i ) 
		{
			if ( str.charAt( i ) != ' ' && str.charAt( i ) != '\t' ) 
			{
				endIdx = i;
				break;
			}
		}
		for ( int i = startIdx; i <= endIdx; ++i ) 
		{
			outStr += str.charAt( i );
		}
		return outStr;
	}

	public static String removeAllWhiteSpacesFromString_OwnAlgo_Iteratively( String str ) 
	{
		String outStr = "";
		for ( int i = 0; i < str.length(); ++i ) 
		{
			if ( str.charAt( i ) != ' ' && str.charAt( i ) != '\t' ) 
			{
				outStr += str.charAt( i );
			}
		}
		return outStr;
	}

	public static String removeAllWhiteSpacesFromString_OwnAlgo_Recursively( String str ) 
	{
		return removeAllWhiteSpacesFromString_OwnAlgo_Recursively(str, "", 0);
	}

	public static String removeAllWhiteSpacesFromString_OwnAlgo_Recursively( String str, String outStr, int index ) 
	{
		if(index == str.length())
			return outStr;
		else
		{
			if ( str.charAt( index ) != ' ' && str.charAt( index ) != '\t') 
			{
				return removeAllWhiteSpacesFromString_OwnAlgo_Recursively(str, outStr + str.charAt( index ), index + 1);
			}
			else
				return removeAllWhiteSpacesFromString_OwnAlgo_Recursively(str, outStr , index + 1);
		}
	}

  
	public static String removeAllWhiteSpacesFromString_StringTokenizer_Iteratively( String str ) 
	{
		String outStr = "";
		StringTokenizer st = new StringTokenizer( str );
		while ( st.hasMoreTokens() ) 
		{
			outStr += st.nextToken();
		}
		return outStr;
	}
}