class Solution {
    public int orangesRotting(int[][] grid) {
        HashSet<Point> rotten = new HashSet<Point>();
        HashSet<Point> fresh = new HashSet<Point>();
        for(int r = 0; r < grid.length; r++) {
            for(int c = 0; c < grid[r].length; c++) {
                if (grid[r][c] == 2) {
                    rotten.add(new Point(r,c));
                    System.out.println("Rotten r: " + r + " c: " + c);
                }
                if ( grid[r][c] == 1) {
                    fresh.add(new Point(r,c));
                    System.out.println("Fresh r: " + r + " c: " + c);
                }
            }
        }
        if ( fresh.isEmpty()) {
            return 0;
        }
        int count = 0;
        HashSet<Point> newRotten = new HashSet<Point>();
        while (!fresh.isEmpty() && !rotten.isEmpty()) {
            for(Point p: rotten) {
                ArrayList<Point> neighbors = getNeighbors(p, fresh);
                for(Point n: neighbors) {
                    newRotten.add(n);
                }
            }
            if(newRotten.isEmpty() && !fresh.isEmpty()) {
                return -1;
            }
            rotten.clear();
            for(Point r: newRotten) {
                rotten.add(r);
            }
            System.out.println(count);
            newRotten.clear();
            count++;
        }
        return count;
    }

    private static ArrayList<Point> getNeighbors(Point p, HashSet<Point> fresh) {
        int r = p.r;
        int c = p.c;
        Point top = new Point(r - 1, c);
        Point bot = new Point(r + 1, c);
        Point left = new Point(r, c + 1);
        Point right = new Point(r, c - 1);
        ArrayList<Point> points = new ArrayList<Point>();
        if (fresh.contains(top)) {
            points.add(top);
            fresh.remove(top);
        }
        if(fresh.contains(left)){
            points.add(left);
            fresh.remove(left);
        }
        if(fresh.contains(right)){
            points.add(right);
            fresh.remove(right);
        }
        if(fresh.contains(bot)) {
            points.add(bot);
            fresh.remove(bot);
        }
        System.out.println(points);
        return points;
    }
}

class Point {
    public final int r;
    public final int c;

    public Point (int r, int c ) {
        this.r = r;
        this.c = c;
    }

    public boolean equals(Object b) {
        if ( b == this ) {
            return true;
        }
        Point comp = (Point) b;
        if (this.r == comp.r && this.c == comp.c) {
            return true;
        }
        return false;
    }
}