求调！！！

#include<iostream>
using namespace std;
const int minn=-1e9-1;
const int N=1e6+6;
int n,q;
int a[N];
int op,l,r,x;
int f[N<<2];
int xg[N<<2],jia[N<<2];
bool visxg[N<<2];
int ans;
void build(int l,int r,int i){
    if(l==r){
        f[i]=a[l];
        return ;
    }
    int mid=(l+r)/2;
    build(l,mid,i*2);
    build(mid+1,r,i*2+1);
    f[i]=max(f[i*2],f[i*2+1]);
}
void tree1(int l,int r,int sl,int sr,int s,int i){
    if(l==r||(l==sl&&r==sr)){
        visxg[i]=1,xg[i]=s;
        jia[i]=0;
        f[i]=s;
        return ;
    }
    int mid=(l+r)/2;
    if(visxg[i]!=0) f[i*2]=xg[i],f[i*2+1]=xg[i],visxg[i]=0;
    f[i*2]+=jia[i],f[i*2+1]+=jia[i],jia[i]=0;
    if(sl<=mid) tree1(l,mid,sl,min(sr,mid),s,i*2);
    if(sr>mid) tree1(mid+1,r,max(sl,mid+1),sr,s,i*2+1);
    f[i]=max(f[i*2],f[i*2+1]);
}
void tree2(int l,int r,int sl,int sr,int s,int i){
    if(l==r||(l==sl&&r==sr)){
        jia[i]+=s;
        f[i]+=s;
        return ;
    }
    int mid=(l+r)/2;
    if(visxg[i]!=0) f[i*2]=xg[i],f[i*2+1]=xg[i],visxg[i]=0;
    f[i*2]+=jia[i],f[i*2+1]+=jia[i],jia[i]=0;
    if(sl<=mid) tree2(l,mid,sl,min(sr,mid),s,i*2);
    if(sr>mid) tree2(mid+1,r,max(sl,mid+1),sr,s,i*2+1);
    f[i]=max(f[i*2],f[i*2+1]);
}
void tree3(int l,int r,int sl,int sr,int i){
    if(l==r||(l==sl&&r==sr)){
        ans=max(ans,f[i]);
        return ;
    }
    int mid=(l+r)/2;
    if(visxg[i]!=0) f[i*2]=xg[i],f[i*2+1]=xg[i],visxg[i]=0;
    f[i*2]+=jia[i],f[i*2+1]+=jia[i],jia[i]=0;
    if(sl<=mid) tree3(l,mid,sl,min(sr,mid),i*2);
    if(sr>mid) tree3(mid+1,r,max(sl,mid+1),sr,i*2+1);
}
int main(){
    scanf("%d%d",&n,&q);
    for(int i=1;i<=n;i++) scanf("%d",&a[i]);
    build(1,n,1);
    while(q--){
        scanf("%d%d%d",&op,&l,&r);
        if(op==1){
            scanf("%d",&x);
            tree1(1,n,l,r,x,1);
        }
        else if(op==2){
            scanf("%d",&x);
            tree2(1,n,l,r,x,1);
        }
        else{
            ans=minn;
            tree3(1,n,l,r,1);
            printf("%d\n",ans);
        }
    }
    return 0;
}