```cpp
int mul(int x, int y) {
return static_cast<long long>(x) * y % mod;
}
int add(int x, int y) {
return ((x + y) % mod + mod) % mod;
}
```
by szTom @ 2022-01-20 10:22:12
@[szTom](/user/108422) 谢谢，解决了
by Controls_Wishes @ 2022-01-20 13:48:11