```cpp for(int i=1;i<=n;i++){ if(w[i]>=mid){ sw[i]=sw[i-1]+1; sv[i]=sv[i-1]+v[i]; }else{ sw[i]-sw[i-1]; sv[i]=sv[i-1]; } } ``` 这一段前缀和里的 sw[i]-sw[i-1]; 等号写成减号了 by Zhr100102 @ 2023-12-10 22:24:04