@[zjx120213](/user/855999) x-2,y-2有可能会到负数。
by maokaiyu @ 2024-04-10 21:44:57
@[zjx120213](/user/855999) 如果有帮助，请给个关注
by maokaiyu @ 2024-04-10 21:45:50
@[zjx120213](/user/855999)
```cpp
a[x - 1][y - 2] = a[x - 1][y + 2] = a[x - 2][y - 1] = a[x - 2][y + 1] = -1;
a[x + 1][y - 2] = a[x + 1][y + 2] = a[x + 2][y - 1] = a[x + 2][y + 1] = -1;
```
其中访问`a[x-2]`可能会是`a[-1]`越界，这么写要先特判，或者读入之后所有点坐标都向右下移动1格，防止数组访问越界。
by Nail9 @ 2024-04-16 19:17:54