已经调了一晚上了，救救孩子吧！
by firstlight @ 2023-08-17 23:29:26
@[firstlight](/user/467357) pushdown错了，f1和f2是可以同时存在的，比如你先区间赋1，在区间+2，那最后的结果就是区间的值全为3
by TimeLimitEnough @ 2023-08-18 08:52:26
感谢大佬
by firstlight @ 2023-08-18 09:45:22
@[TimeLimitEnough](/user/1052984)
```cpp
// Ptr[u]blem: P1253 扶苏的问题
// Contest: Luogu
// URL: https://www.luogu.com.cn/ptr[u]blem/P1253
// Memory Limit: 512 MB
// Time Limit: 2000 ms
//
// Powered by CP Editor (https://cpeditor.org)
#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
const int N=1000010;
const ll INF=1e18;
int n,q;
int w[N];
struct Node{
int l,r;
ll Max,f1,f2;
}tr[N*4];
void pushup(int u)
{
tr[u].Max=max(tr[u<<1].Max,tr[u<<1|1].Max);
}
void pushdown(int u)
{
if(tr[u].f1 < INF)
{
tr[u<<1].f1=tr[u].f1;
tr[u<<1].Max=tr[u].f1;
tr[u<<1|1].f1=tr[u].f1;
tr[u<<1|1].Max=tr[u].f1;
tr[u].f1=INF;
}
else if(tr[u].f2)
{
if (tr[u<<1].f1 != INF)
tr[u<<1].f1+=tr[u].f2;
else tr[u<<1].f2+=tr[u].f2;
tr[u<<1].Max+=tr[u].f2;
if (tr[u<<1|1].f1 != INF)
tr[u<<1|1].f1 += tr[u].f2;
else tr[u<<1|1].f2+=tr[u].f2;
tr[u<<1|1].Max+=tr[u].f2;
tr[u].f2=0;
}
}
void build(int u,int l,int r)
{
if(l==r) tr[u]={l,r,w[r],INF,0};
else
{
tr[u]={l,r,0,INF,0};
int mid=l+r>>1;
build(u<<1,l,mid);
build(u<<1|1,mid+1,r);
pushup(u);
}
}
void modify(int u,int l,int r,ll f,ll a)
{
if(tr[u].l>=l&&tr[u].r<=r)
{
if(f!=INF)
{
tr[u].Max=f;
tr[u].f1=f;
tr[u].f2=0;
}
else
{
if (tr[u].f1 != INF)
{
tr[u].f1 += a;
tr[u].Max+=a;
}
else
{
tr[u].Max+=a;
tr[u].f2+=a;
}
}
}
else
{
pushdown(u);
int mid=tr[u].l+tr[u].r>>1;
if(l<=mid) modify(u<<1,l,r,f,a);
if(r>mid) modify(u<<1|1,l,r,f,a);
pushup(u);
}
}
ll query(int u,int l,int r)
{
if(tr[u].l>=l&&tr[u].r<=r) return tr[u].Max;
ll res = -INF;
pushdown(u);
int mid=tr[u].l+tr[u].r>>1;
if(l<=mid) res = max(res, query(u<<1,l,r));
if(r>mid) res = max(res, query(u<<1|1,l,r));
return res;
}
int main()
{
scanf("%d%d",&n,&q);
for(int i=1;i<=n;i++) scanf("%d",&w[i]);
build(1,1,n);
int op,l,r,x;
while(q--)
{
scanf("%d%d%d",&op,&l,&r);
if(op==1)
{
scanf("%d",&x);
modify(1,l,r,x,0);
}
else if(op==2)
{
scanf("%d",&x);
modify(1,l,r,INF,x);
}
else
{
printf("%lld\n",query(1,l,r));
// for(int i=1;i<=n;i++) printf("%lld ",query(1,i,i));
// printf("\n");
}
// for(int i=1;i<=80;i++) printf("%d %d %lld %lld %lld\n",tr[i].l, tr[i].r, tr[i].f2, tr[i].Max, tr[i].f1);
// printf("\n");
}
return 0;
}
```
by firstlight @ 2023-08-18 09:56:13
改成这样？
by firstlight @ 2023-08-18 09:56:47
似乎还不行
by firstlight @ 2023-08-18 09:57:35