Need help writing a toString
I have no idea how to go about writing the toString method for this code. I have to print the array that provides the longest sequence. I would appreciate your help.
Here is the code:import java.io.FileReader;
import java.io.IOException;
import java.util.List;
import java.util.ArrayList;
import java.util.Scanner;
import java.util.StringTokenizer;
class Grid
{
privateint [ ][ ] mainGrid;
public Grid( String file )throws IOException
{
FileReader fr =new FileReader( file );
Scanner scan =new Scanner( fr );
ArrayList<ArrayList><Integer>> numR =new ArrayList<ArrayList><Integer>>( );
while( scan.hasNextLine( ) )
{
String line = scan.nextLine( );
StringTokenizer st =new StringTokenizer ( line );
String number;
ArrayList<Integer> numC =new ArrayList<Integer>( );
while( st.hasMoreTokens( ) )
{
number = st.nextToken( );
int num = Integer.parseInt(number);
numC.add(num);
}
numR.add( numC );
}
int height = numR.size();
int width = numR.get( 0 ).size();
mainGrid =newint [height][width];
for(int i = 0; i < height; i++)
{
for(int j = 0; j < width; i++)
{
mainGrid [ i ][ j ] = numR.get( i ).get( j );
}
}
}
privateclass Position
{
privateint row;
privateint col;
public Position(int r,int c )
{
r = row;
c = col;
}
public List<Position> getAdjacents( )
{
int lowRow = row != 0 ? row - 1 : 0;
int lowCol = col != 0 ? col - 1 : 0;
int highRow = row != mainGrid.length - 1 ? row + 1 : mainGrid.length - 1;
int highCol = col != mainGrid[ 0 ].length - 1 ? col + 1 : mainGrid[ 0 ].length - 1;
List<Position> result =new ArrayList<Position>( );
for(int r = lowRow; r <= highRow; r++ )
for(int c = lowCol; c <= highCol; c++ )
if( r != row || c != col )
result.add(new Position( r, c ) );
return result;
}
publicboolean equals( Object other )
{
if( ! ( otherinstanceof Position ) )
returnfalse;
Position rhs = (Position) other;
return row == rhs.row && col == rhs.col;
}
publicint getValue( )
{
return mainGrid [ row ][ col ];
}
public String toString( )
{
return"(" + row +"," + col +")";
}
}
public Position newPosition(int r ,int c )
{
returnnew Position( r, c );
}
// Public driver
public List<Position> getSequence( )
{
List<Position> sequence =new ArrayList<Position>( );
for(int r = 0; r < mainGrid.length - 1; r++)
{
for(int c = 0; c < mainGrid[ 0 ].length - 1; c++)
{
sequence = getSequence(new Position( r, c ));
}
}
return sequence;
}
// Recursive routine
private List<Position> getSequence( Position pos )
{
List<Position> adj = pos.getAdjacents( );
if( adj.size( ) == 0)
{
List<Position> seq =new ArrayList<Position>( );
seq.add( pos );
return seq;
}
List<Position> maxSeq =null;
for( Position p: adj)
{
List<Position> currentSeq = getSequence( p );
if( currentSeq.size( ) < maxSeq.size( ))
maxSeq = currentSeq;
}
maxSeq.add( pos );
return maxSeq;
}
public String toString( )
{
StringBuffer sb =new StringBuffer( );
returnnew String( sb );
}
}
class MaxSubsequence
{
publicstaticvoid main( String [ ] args )
{
try
{
System.out.println(new Grid("numbergrid1.txt" ));
}
catch( IOException e)
{
System.err.println("Error opening file");
}
}
}
