@[123789456ye](/space/show?uid=207090) pushdown是把值传给两个子节点，应该用子节点的长度
by Llf0703 @ 2019-06-30 18:03:25
```
#define len(x) sn[x].r-sn[x].l+1
inline void pushdown(int rt)
{
if(sn[rt].lazy)
{
sn[rt<<1].lazy+=sn[rt].lazy;
sn[rt<<1|1].lazy+=sn[rt].lazy;
sn[rt<<1].val+=sn[rt].lazy*len(rt<<1);
sn[rt<<1|1].val+=sn[rt].lazy*len(rt<<1|1);
sn[rt<<1].val%=mod;
sn[rt<<1|1].val%=mod;
sn[rt].lazy=0;
}
}
```
这是原来的部分@[Llf0703](/space/show?uid=29696)
[记录](https://www.luogu.org/recordnew/show/20171519)
by 123789456ye @ 2019-06-30 20:50:42