这是什么意思?
```cpp
int j=x-a[i-1];
sum+=a[i]-j;
a[i]=j;
```
by pjr_freopen @ 2024-04-09 22:54:30
@[pjr_freopen](/user/1033544) j是前一个和x的差,sum加上a[i]与a[i-1]比x还多的值,
by XZY1020932680 @ 2024-04-09 23:06:15