要是大佬看不清合并过程看这里
```cpp
for(int i=0;i<len;++i)
res[i]=(
(((long long)(E[i].r+0.5)%P)<<30)%P
+(((long long)(F[i].r+0.5)%P)<<15)%P
+(((long long)(G[i].r+0.5)%P)<<15)%P
+(((long long)(H[i].r+0.5)%P)%P)
)%P;
```
by 小菜鸟 @ 2018-07-20 16:11:57
%%%
by Viston @ 2018-07-20 16:29:47