Erratic Ants problem from ACM competition qualification

erraticants.java

// Created by James Trimble (On Twitter @jamestrimble)
// Original problem can be found here, https://icpc-qual-13.contest.scrool.se/problems/erraticants
public class erraticants {

    public static Room[][] map;
    public static void main(String[] args) {
        int problem = 2;
        String path;

        switch (problem) {
            case 0:
                path = "SEEENWSS";
                break;
            case 1:
                path = "SEN";
                break;
            default:
                path = "SENW";
                break;
        }

        System.out.println("Solution = "+solveants(path));
    }

    public static Integer solveants(String path) {
        map = new Room[path.length()][path.length()];
        for (int i = 0; i < path.length(); i++) {
            for (int j = 0; j < path.length(); j++) {
                map[i][j] = new Room();
            }
        }

        int x = 0, y = 0;
        map[x][y].setValue(999);
        for (int i = 0; i < path.length(); i++) {
            String direction = path.substring(i,i+1);
            if (direction.equals("N")) {
                map[x][y].setWall(Room.North, 0);
                map[x][y-1].setWall(Room.South, 0);
                y = Math.max(y-1,0);
            }
            else if (direction.equals("S")) {
                map[x][y].setWall(Room.South, 0);
                map[x][y+1].setWall(Room.North, 0);
                y = Math.min(y+1,path.length()-1);
            }
            else if (direction.equals("E")) {
                map[x][y].setWall(Room.East, 0);
                map[x+1][y].setWall(Room.West, 0);
                x = Math.min(x+1,path.length()-1);
            }
            else if (direction.equals("W")) {
                map[x][y].setWall(Room.West, 0);
                map[x-1][y].setWall(Room.East, 0);
                x = Math.max(x-1,0);
            }

            map[x][y].setValue(999);
        }

        int destX = x, destY = y;
        update(destX, destY, -1);
        return map[0][0].getValue();
    }

    public static void update(int x, int y, int value) {
        if (x < 0 || y < 0 || x >= map[0].length || y >= map[0].length || map[x][y].getValue() <= value) { return; }
        map[x][y].setValue(value+1);
        if (map[x][y].northClear()) { update(x,y-1,map[x][y].getValue()); }
        if (map[x][y].southClear()) { update(x,y+1,map[x][y].getValue()); }
        if (map[x][y].eastClear()) { update(x+1,y,map[x][y].getValue()); }
        if (map[x][y].westClear()) { update(x-1,y,map[x][y].getValue()); }
    }

}

class Room {
    public final static Integer North = 0, South = 1, East = 2, West = 3;
    Integer walls[] = {1,1,1,1}; // North, South, East, West; All walls blocked by default
    Integer value = 0;

    boolean northClear() { return !walls[0].equals(1); }
    boolean southClear() { return !walls[1].equals(1); }
    boolean eastClear() { return !walls[2].equals(1); }
    boolean westClear() { return !walls[3].equals(1); }

    void setWall(Integer wall, Integer value) { walls[wall] = value; }
    Integer getWall(Integer wall) { return walls[wall]; }

    void setValue(Integer value) { this.value = value; }
    Integer getValue() { return this.value; }
}