蒟蒻求助！60分，7、8、9、10WA

#include<cstdio>
#include<algorithm>
#define int long long
using namespace std;
inline int max(int a,int b)
{
    return a>b?a:b;
}
inline int read()
{
    int x=0,y=1;
    char c=getchar();
    while(c>'9'||c<'0')
    {
        if(c=='-')
            y=-1;
        c=getchar();
    }
    while(c<='9'&&c>='0')
        x=x*10+c-48,c=getchar();
    return x*y;
}
const int N=1000001,INF=9223372036854775807;
struct kof{
    int sum,tag,tagb;
    bool used;
}tree[N<<2];
int a[N],n,m;
void build(int k,int l,int r)
{
    if(l==r)
    {
        tree[k].sum=a[l];
        return;
    }
    int mid=l+r>>1;
    build(k<<1,l,mid);
    build(k<<1|1,mid+1,r);
    tree[k].sum=max(tree[k<<1].sum,tree[k<<1|1].sum);
    return;
}
inline void adda(int k,int v)
{
    tree[k].tag+=v;
    tree[k].sum+=v;
    return;
}
inline void addb(int k,int v)
{
    tree[k].tagb+=v;
    tree[k].sum=tree[k].tagb;
    tree[k].used=true;
    return;
}
inline void pushdown(int k)
{
    if(tree[k].used)
    {
        tree[k<<1].tag=tree[k].tag;
        tree[k<<1].tagb=tree[k].tagb;
        tree[k<<1].sum=tree[k].tag+tree[k].tagb;
        tree[k<<1].used=true;
        tree[k<<1|1].tag=tree[k].tag;
        tree[k<<1|1].tagb=tree[k].tagb;
        tree[k<<1|1].sum=tree[k].tag+tree[k].tagb;
        tree[k<<1|1].used=true;
    }
    else
    {
        tree[k<<1].tag+=tree[k].tag;
        tree[k<<1].sum+=tree[k].tag;
        tree[k<<1|1].tag+=tree[k].tag;
        tree[k<<1|1].sum+=tree[k].tag;
    }
    tree[k].tag=0;
    tree[k].tagb=0;
    tree[k].used=false;
    return;
}
void update(int k,int l,int r,int x,int y,int v)
{
    if(x<=l&&r<=y)
    {
        adda(k,v);
        return;
    }
    pushdown(k);
    int mid=l+r>>1;
    if(x<=mid)
        update(k<<1,l,mid,x,y,v);
    if(y>mid)
        update(k<<1|1,mid+1,r,x,y,v);
    tree[k].sum=max(tree[k<<1].sum,tree[k<<1|1].sum);
    return;
}
void updateb(int k,int l,int r,int x,int y,int v)
{
    if(x<=l&&r<=y)
    {
        addb(k,v);
        return;
    }
    pushdown(k);
    int mid=l+r>>1;
    if(x<=mid)
        updateb(k<<1,l,mid,x,y,v);
    if(y>mid)
        updateb(k<<1|1,mid+1,r,x,y,v);
    tree[k].sum=max(tree[k<<1].sum,tree[k<<1|1].sum);
    return;
}
int query(int k,int l,int r,int x,int y)
{
    if(l>y||r<x) return -INF;
    if(l>=x&&r<=y)
        return tree[k].sum;
    int mid=l+r>>1;
    pushdown(k);
    return max(query(k<<1,l,mid,x,y),query(k<<1|1,mid+1,r,x,y));
}
signed main()
{
    int x,y,v;
    n=read(),m=read();
    for(int i=1;i<=n;i++)
        a[i]=read();
    build(1,1,n);
    for(int i=1;i<=m;i++)
    {
        int q=read();
        if(q==1)
        {
            x=read(),y=read(),v=read();
            updateb(1,1,n,x,y,v);
        }
        if(q==2)
        {
            x=read(),y=read(),v=read();
            update(1,1,n,x,y,v);
        }
        if(q==3)
        {
            x=read(),y=read();
            printf("%lld\n",query(1,1,n,x,y));
        }
    }
}