Kon.java

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package kon;
 
import java.awt.Point;
import java.util.LinkedList;
import java.util.Queue;
import java.util.Scanner;
 
/**
 *
 * @author student
 */
public class Kon {
 
    private static boolean[][] map;
    private static int sx, sy, rx, ry, ex, ey;
    private static Queue<Point> st;
    private static int sol;
 
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
 
        int[][] podm = {{1,2},{2,1},{2, -1},{1,-2}, {-1,-2}, {-2,-1},{-2,1},{-1,2}};
 
        while(sc.hasNextInt())
        {
            rx = sc.nextInt();
            ry = sc.nextInt();
            sx = sc.nextInt();
            sy = sc.nextInt();
            ex = sc.nextInt();
            ey = sc.nextInt();
 
            st = new LinkedList<Point>();
 
            map = new boolean[rx+1][ry+1];
            sol = 1;
 
            map[sx][sy] = true;
            st.offer(new Point(sx, sy));
            st.offer(null);
 
            while(true)
            {
                if(st.size() == 1)
                {
                    System.out.println("impossible");
                    break;
                }
                //System.out.println(st.size());
                Point p = st.remove();
 
                if(p == null)
                {
                    st.add(null);
                    sol++;
                    continue;
                }
 
                int x, y;
                boolean mimo = false;
                for(int j=0; j<8; j++)
                {
                    x = p.x + podm[j][0];
                    y = p.y + podm[j][1];
 
                    if(0 < x && x <= rx && 0 < y && y <= ry)
                    {
                        mimo = solve(x, y);
                        if(mimo) break;
                    }
                }
                if(mimo) break;
 
                /*if(p.x-2 > 0)
                {
                    if(p.y+1 <= ry)
                    {
                        if(solve(p.x-2, p.y+1))
                            break;
                    }
                    else if(p.y-1 > 0)
                    {
                        if(solve(p.x-2, p.y-1))
                            break;
                    }
                }
                //atd
                
                if(p.x+1 <= rx)
                {
                    if(p.y+2 <= ry)
                    {
                        if(solve(p.x+1, p.y+2))
                            break;
                    }
                    else if(p.y-2 > 0)
                    {
                        if(solve(p.x+1, p.y-2))
                            break;
                    }
                }
                
                if(p.x+2 <= rx)
                {
                    if(p.y+1 <= ry)
                    {
                        if(solve(p.x+2, p.y+1))
                            break;
                    }
                    else if(p.y-1 > 0)
                    {
                        if(solve(p.x+2, p.y-1))
                            break;
                    }
                }
                
                //ds
                
               if(p.y-1 > 0)
                {
                    if(p.x+2 <= rx)
                    {
                        if(solve(p.x+2, p.y-1))
                            break;
                    }
                    else if(p.x-2 > 0)
                    {
                        if(solve(p.x-2,  p.y-1))
                            break;
                    }
                }
                
                if(p.y-2 > 0)
                {
                    if(p.x+1 <= rx)
                    {
                        if(solve(p.x+1, p.y-2))
                            break;
                    }
                    else if(p.x-1 > 0)
                    {
                        if(solve(p.x-1, p.y-2))
                            break;
                    }
                }
                
                //
                
                if(p.y+1 <= ry)
                {
                    if(p.x+2 <= rx)
                    {
                        if(solve(p.x+2, p.y+1))
                            break;
                    }
                    else if(p.x-2 > 0)
                    {
                        if(solve(p.x-2,  p.y+1))
                            break;
                    }
                }
                
                if(p.y+2 <= ry)
                {
                    if(p.x+1 <= rx)
                    {
                        if(solve(p.x+1, p.y+2))
                            break;
                    }
                    else if(p.x-1 > 0)
                    {
                        if(solve(p.x-1, p.y+2))
                            break;
                    }
                }*/
 
            }
        }
    }
 
    private static boolean solve(int x, int y)
    {
        if(!map[x][y])
        {
            if(x == ex && y == ey)
            {
                 System.out.println(sol);
                return true;
            }
            else
            {
                st.offer(new Point(x, y));
                map[x][y] = true;
            }
        }
 
        return false;
    }
}