神奇的头像
by MikukuOvO @ 2019-12-27 20:10:08
@[蕉♂灼](/user/114164)
by Serenata_Immortale @ 2019-12-27 20:20:13
您好像忘了个取模：
```cpp
ansi = (ansi + 1ll * ki * f[i] * fp((x - i) % mod, mod - 2) % mod * inv[i - 1] % mod * inv[k + 2 - i] % mod + mod) % mod;
```
改为
```cpp
ansi = (ansi + 1ll * ki * f[i] %mod * fp((x - i) % mod, mod - 2) % mod * inv[i - 1] % mod * inv[k + 2 - i] % mod + mod) % mod;
```
by Serenata_Immortale @ 2019-12-27 20:23:43
@[pathogen](/user/85058) ki是+-1
by lprdsb @ 2019-12-27 20:24:24