疯狂线段树90pts求调

#include<bits/stdc++.h>
using namespace std;
int n,m,a[1000005],k,x,y,z;
long long b[4000005],c[4000005][2];
void build(int x,int l,int r)
{
    if (l==r)
    b[x]=a[l];
    else
    {
        int mid=l+r>>1;
        build(x<<1,l,mid);
        build(x<<1|1,mid+1,r);
        b[x]=max(b[x<<1],b[x<<1|1]);
    }
    c[x][0]=0x7fffffffffffffff;
}
void cover(int x)
{
    if (c[x][0]!=0x7fffffffffffffff)
    {
        b[x<<1]=c[x][0];
        b[x<<1|1]=c[x][0];
        c[x<<1][0]=c[x][0];
        c[x<<1|1][0]=c[x][0];
        c[x<<1][1]=0;
        c[x<<1|1][1]=0;
        c[x][0]=0x7fffffffffffffff;
    }
}
void pushdown(int x,int l,int r)
{
    cover(x);
    if (c[x][1])
    {
        int mid=l+r>>1;
        cover(x);
        b[x<<1]+=c[x][1];
        b[x<<1|1]+=c[x][1];
        c[x<<1][1]+=c[x][1];
        c[x<<1|1][1]+=c[x][1];
        c[x][1]=0;
    }
}
void modify1(int x,int bl,int br,int l,int r,int y)
{
    if (l<=bl && br<=r)
    {
        b[x]=y;
        c[x][0]=y;
        c[x][1]=0;
    }
    else
    {
        int mid=bl+br>>1;
        pushdown(x,bl,br);
        if (l<=mid)
        modify1(x<<1,bl,mid,l,r,y);
        if (mid<r)
        modify1(x<<1|1,mid+1,br,l,r,y);
        b[x]=max(b[x<<1],b[x<<1|1]);
    }
}
void modify2(int x,int bl,int br,int l,int r,int y)
{
    if (l<=bl && br<=r)
    {
        cover(x);
        b[x]+=y;
        c[x][1]+=y;
    }
    else
    {
        int mid=bl+br>>1;
        pushdown(x,bl,br);
        if (l<=mid)
        modify2(x<<1,bl,mid,l,r,y);
        if (mid<r)
        modify2(x<<1|1,mid+1,br,l,r,y);
        b[x]=max(b[x<<1],b[x<<1|1]);
    }
}
long long query(int x,int bl,int br,int l,int r)
{
    if (l<=bl && br<=r)
    return b[x];
    int mid=bl+br>>1;
    long long result=-0x8000000000000000;
    pushdown(x,bl,br);
    if (l<=mid)
    result=max(result,query(x<<1,bl,mid,l,r));
    if (mid<r)
    result=max(result,query(x<<1|1,mid+1,br,l,r));
    return result;
}
int main()
{
    cin>>n>>m;
    for (int i=1;i<=n;++i)
    scanf("%d",&a[i]);
    build(1,1,n);
    while (m--)
    {
        scanf("%d",&k);
        if (k==1)
        {
            scanf("%d%d%d",&x,&y,&z);
            modify1(1,1,n,x,y,z);
        }
        else if (k==2)
        {
            scanf("%d%d%d",&x,&y,&z);
            modify2(1,1,n,x,y,z);
        }
        else
        {
            scanf("%d%d",&x,&y);
            cout<<query(1,1,n,x,y)<<'\n';
        }
    }
}