@[operator_](/user/499682) 你估错了，应该是 $C_{m}^{c} n^3$，最大原子操作大约是 $12870 \times 4096 = 52715520$，不会超时
by SkyWave @ 2023-03-18 14:35:44
@[SkyWave](/user/234992) thx
by operator_ @ 2023-03-18 14:44:47