import java.io.* ;/** * simple methods for basic input/output (Java 1.1) * @author Roger Garside * @version Last Rewritten: 16/Sept/97 */public class BasicIo    {     /**     * output a prompt message to the screen     * @param prompt message     */    public static void prompt(String s)	{	System.err.print(s) ;	System.err.flush() ;	} // end of method prompt    /**     * read the next line from the keyboard as a String     * @return the line as a String     */    public static String readString() throws IOException        {	BufferedReader in = new BufferedReader(new					InputStreamReader(System.in)) ;        return in.readLine() ;        } // end of method readString    /**     * read a character, the first on the line     * @return the first character on the line     */    public static char readCharacter() throws IOException        {	BufferedReader in = new BufferedReader(new					InputStreamReader(System.in)) ;        String s = in.readLine() ;	if (s.length() == 0)            return ' ' ;        else	    return s.charAt(0) ;        } // end of method readCharacter    /**     * read the next line from the keyboard as an integer     * @return the line as an integer     */    public static int readInteger() throws IOException        {        String line ;	BufferedReader in = new BufferedReader(new					InputStreamReader(System.in)) ;        try            {            line = in.readLine() ;            int i = Integer.parseInt(line.trim()) ;            return i ;            }        catch (Exception e)            {            throw new IOException("invalid integer") ;            }        } // end of method readInteger    /**     * read the next line from the keyboard as a float     * @return the line as a float     */    public static float readFloat() throws IOException        {        String line ;	BufferedReader in = new BufferedReader(new					InputStreamReader(System.in)) ;        try            {            line = in.readLine() ;            return Float.valueOf(line.trim()).floatValue() ;            }        catch (Exception e)            {            throw new IOException("invalid float") ;            }        } // end of method readFloat    /**     * read the next line from the keyboard as a double     * @return the line as a double     */    public static double readDouble() throws IOException        {        String line ;	BufferedReader in = new BufferedReader(new					InputStreamReader(System.in)) ;        try            {            line = in.readLine() ;            return Double.valueOf(line.trim()).doubleValue() ;            }        catch (Exception e)            {            throw new IOException("invalid double") ;            }        } // end of method readDouble    /**     * output an integer in a field of a specified width     * @param n the integer to be output     * @param w the width of the field     */    public static void writeInteger(int n, int w)        {        Integer n1 = new Integer(n) ;        String t = n1.toString() ;        if (t.length() > w)            System.out.print(t) ;        else            {            for (int i = 0 ; i < w - t.length() ; i++)                System.out.print(' ') ;            System.out.print(t) ;            }        } // end of method writeInteger    /**     * output a float in a field of a specified width     * @param n the float to be output     * @param w the width of the field     * @param d the number of decimal places     */    public static void writeFloat(float n, int w, int d) throws IOException	{	Float n1 = new Float(n) ;	String t = n1.toString() ;	//System.err.println("string is **" + t + "**") ;	if (t.indexOf('e') != -1)	    throw new IOException("out of range") ;        if (d < 1)	    throw new IOException("invalid 3rd argument") ;	boolean negative = false ;	if (t.charAt(0) == '-')	    {	    negative = true ;	    t = t.substring(1) ;	    }	int index = t.indexOf('.') ;	int decimals ;	if (index == -1)	    decimals = 0 ;	else	    {	    decimals = t.length() - index - 1 ;            if (decimals <= 0)		throw new IOException("funny format") ;	    }	if (decimals < d)	    {	    if (decimals == 0)		t += '.' ;	    for (int i = 0 ; i < d - decimals ; i++)		t += '0' ;	    }	else if (decimals > d)	    {	    int offset = t.length() - decimals + d ;	    if (t.charAt(offset) < '5')		t = t.substring(0, t.length() - decimals + d) ;	    else		{		StringBuffer sb = new StringBuffer(t) ;		offset-- ;		while ((offset >= 0) &&		       ((sb.charAt(offset) == '9') ||		        (sb.charAt(offset) == '.')))		    {		    if (sb.charAt(offset) == '9')		        sb.setCharAt(offset, '0') ;		    offset-- ;		    }		if (offset >= 0)		    {		    sb.setCharAt(offset,	Character.forDigit(Character.digit(sb.charAt(offset), 10) + 1, 10)) ;	t = sb.toString().substring(0, t.length() - decimals + d) ;		    }		else	t = '1' + sb.toString().substring(0, t.length() - decimals + d) ;		}	    }	if (negative)	    t = '-' + t ;	if (t.length() > w)	    System.out.print(t) ;	else	    {	    for (int i = 0 ; i < w - t.length() ; i++)		System.out.print(' ') ;	    System.out.print(t) ;	    }	} // end of method writeFloat    /**     * output a double in a field of a specified width     * @param n the double to be output     * @param w the width of the field     * @param d the number of decimal places     */    public static void writeDouble(double n, int w, int d) throws IOException	{	Double n1 = new Double(n) ;	String t = n1.toString() ;	//System.err.println("string is **" + t + "**") ;	if (t.indexOf('e') != -1)	    throw new IOException("out of range") ;        if (d < 1)	    throw new IOException("invalid 3rd argument") ;	boolean negative = false ;	if (t.charAt(0) == '-')	    {	    negative = true ;	    t = t.substring(1) ;	    }	int index = t.indexOf('.') ;	int decimals ;	if (index == -1)	    decimals = 0 ;	else	    {	    decimals = t.length() - index - 1 ;            if (decimals <= 0)		throw new IOException("funny format") ;	    }	if (decimals < d)	    {	    if (decimals == 0)		t += '.' ;	    for (int i = 0 ; i < d - decimals ; i++)		t += '0' ;	    }	else if (decimals > d)	    {	    int offset = t.length() - decimals + d ;	    if (t.charAt(offset) < '5')		t = t.substring(0, t.length() - decimals + d) ;	    else		{		StringBuffer sb = new StringBuffer(t) ;		offset-- ;		while ((offset >= 0) &&		       ((sb.charAt(offset) == '9') ||		        (sb.charAt(offset) == '.')))		    {		    if (sb.charAt(offset) == '9')		        sb.setCharAt(offset, '0') ;		    offset-- ;		    }		if (offset >= 0)		    {		    sb.setCharAt(offset,	Character.forDigit(Character.digit(sb.charAt(offset), 10) + 1, 10)) ;	t = sb.toString().substring(0, t.length() - decimals + d) ;		    }		else	t = '1' + sb.toString().substring(0, t.length() - decimals + d) ;		}	    }	if (negative)	    t = '-' + t ;	if (t.length() > w)	    System.out.print(t) ;	else	    {	    for (int i = 0 ; i < w - t.length() ; i++)		System.out.print(' ') ;	    System.out.print(t) ;	    }	} // end of method writeDouble    } // end of class BasicIo