Java5

import java.util.*;
import java.io.*;
import java.awt.*;

public class MapDataDrawer
{
  // store map data in grid array
  private int[][] grid;

  // Read 2D array into grid. Data in file "filename", grid is rows x cols
  public MapDataDrawer(String filename, int rows, int cols) throws Exception{
        Scanner readIn = new Scanner(new File(filename));
        grid = new int[rows][cols];
        for (int row = 0; row < rows; row++) {
            for (int col = 0; col < cols; col++) {
                grid[row][col] = readIn.nextInt() ;
            }
        }
    }

  /**
   * @return the min value in the entire grid
   */
  public int findMin(){

      return 0;
  }

  /**
   * @return the max value in the entire grid
   */
  public int findMax(){
      int MAX_VALUE = grid[0][0];
        for (int i = 0; i < grid.length; i++) {
            for (int j = 0; j < grid[i].length; j++) {
                if (grid[i][j] > MAX_VALUE) {
                    MAX_VALUE = grid[i][j];
                }
            }
        }
      return MAX_VALUE;
  }

  /**
   * @param col the column of the grid to check
   * @return the index of the row with the lowest value in the given col for the grid
   */
  public int indexOfMinRow(int col){
      int MIN_VALUE = grid[0][0];
        for (int i = 0; i < grid.length; i++)
        {
            for (int j = 0; j < grid[i].length; j++)
            {
                if (grid[i][j] < MIN_VALUE)
                {
                    MIN_VALUE = grid[i][j];
                }
            }
        }
      return MIN_VALUE;
  }


  /**
   * DON'T CHANGE THIS CODE, except to uncomment it when you instantiate the grid
   * Draws the grid using the given Graphics object.
   * Colors should be grayscale values 0-255, scaled based on min/max values in grid
   */

  // ******ALERT******
  // Note - until you instantiate a grid, through the constructor, this
  // method will generate a null pointer exception, since there is no grid.length
  // ********************
  public void drawMap(Graphics g){

    int minVal = findMin();
    int maxVal = findMax();
    double range = maxVal - minVal;

    for(int row=0; row < grid.length; row++){
      for(int col=0; col<grid[0].length; col++){
         int val = (int)(((grid[row][col]-minVal)/range) * 255);
         //g.setColor(new Color(val,255-val,255-val));
         g.setColor(new Color(val,val,val));
         g.fillRect(col,row,1,1);
        }
    }
  }


   /**
   * Find a path from West-to-East starting at given row.
   * Choose a foward step out of 3 possible forward locations, using greedy method described in assignment.
   * @return the total change in elevation traveled from West-to-East
   */
  public int drawLowestElevPath(Graphics g, int row){
    int currY = row; // row in grid of step one
    // draw initial step - column 0, current row (sent in as parameter)
    g.fillRect(0,row,1,1);

    // Code to compute next step

    // draw next step where x is currently column and currY is row in grid
    int x = 0; // the value of x will be generated by a loop that goes through the
    // columns, but for now, need something to put in "paint" statement
    g.fillRect(x,currY,1,1);

    return 0; // computed change in elevation
  }

  /**
   * @return the index of the starting row for the lowest-elevation-change path in the entire grid.
   */
  public int indexOfLowestElevPath(Graphics g){

      return 0; // row of path with lowest elevation
  }
}