LeetCode : 490. The Maze

[congr]

https://leetcode.com/problems/the-maze/

[congr]

class Solution {
    class Point {
        int x, y;
        Point(int y, int x) {
            this.y = y;
            this.x = x;
        }        
    }

    int[] dy = {-1,0,1,0};
    int[] dx = {0,-1,0,1};
    public boolean hasPath(int[][] maze, int[] start, int[] destination) {
        Queue<Point> q = new LinkedList();
        q.add(new Point(start[0], start[1]));

        boolean[][] visited = new boolean[maze.length][maze[0].length];
        while(!q.isEmpty()) {
            Point p = q.remove();

            if (p.y == destination[0] && p.x == destination[1]) return true;
            for (int d = 0; d < 4; d++) {
                int nx = p.x + dx[d], ny = p.y + dy[d];
                while (inside(ny, nx, maze) && maze[ny][nx] == 0) {
                    nx += dx[d];
                    ny += dy[d];
                }

                nx -= dx[d];
                ny -= dy[d];
                if (visited[ny][nx]) continue;
                q.add(new Point(ny, nx));
                visited[ny][nx] = true;
            }
        }

        return false;
    }

    boolean inside(int y, int x, int[][] maze) {
        if (y>=0 && x>=0 && y<maze.length && x<maze[0].length) return true;
        return false;
    }
}