#39013: 淺顯易懂，內附詳解步驟和圖解。c++(2ms, 368KB)
dylan.jc2222@gmail.com
(chewu)
詳解: https://hackmd.io/@zfzf9bBwQ2OXZj09T60ZjQ/APCS-0107#%E7%AC%AC%E4%BA%8C%E9%A1%8C
提示: 注意邊界
| [x-1][y-1] | [x-1][y] | [x-1][y+1] |
| [x][y-1] | [x][y] | [x][y+1] |
| [x+1][y-1] | [x+1][y] | [x+1][y+1] |