리코쳇 로봇

https://school.programmers.co.kr/learn/courses/30/lessons/169199

import java.util.*;

class Solution {
    public int solution(String[] board) {
        int answer = 0;
        
        int rows = board.length;
        int cols = board[0].length();
                
        int startX = 0, startY = 0, endX = 0, endY = 0;
        
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                if (board[i].charAt(j) == 'R') {
                    startX = i;
                    startY = j;
                }
                if (board[i].charAt(j) == 'G') {
                    endX = i;
                    endY = j;
                }
            }
        }
        
        answer = bfs(startX, startY, endX, endY, rows, cols, board);
    
        return answer;
    }
    
    public int bfs(int sx, int sy, int ex, int ey, int rows, int cols, String[] board)
    {
        int[][] visited = new int[rows][cols];
        int[] dx = {-1, 1, 0, 0};
        int[] dy = {0, 0, -1, 1};
        
        Queue<int[]> queue = new LinkedList<>();
        
        queue.add(new int[]{sx, sy, 0});
        visited[sx][sy] = 1;
        
        while (!queue.isEmpty()) {
            int[] current = queue.poll();
            int x = current[0];
            int y = current[1];
            int count = current[2];
            
            if (x == ex && y == ey) {
                return count;
            }
            
            for (int i = 0; i < 4; i++) {
                int newX = x;
                int newY = y;
                
                while (true) {
                    newX += dx[i];
                    newY += dy[i];
                    
                    if(newX < 0 || newX >= rows)
                        break;
                    
                    if(newY < 0 || newY >= cols)
                        break;
                    
                    if(board[newX].charAt(newY) == 'D')
                        break;
                }
                
                newX -= dx[i];
                newY -= dy[i];
                
                if (newX == ex && newY == ey)
                        return count + 1;
                
                if (visited[newX][newY] == 0 || visited[newX][newY] > count + 1) 
                {
                    visited[newX][newY] = count + 1;
                    queue.add(new int[]{newX, newY, count + 1});
                }
            }
        }
        
        return -1;
    }
}