数组要开 1e6。~~而且这题是 FFT~~
by chenbs @ 2024-02-03 14:47:02
[发帖前请先看讨论区](https://www.luogu.com.cn/discuss/582999)
[您可能想找](https://www.luogu.com.cn/problem/P1303)
by sty0948 @ 2024-02-16 12:42:45