放一个splay先

#include<bits/stdc++.h>
#define clr(a,x) memset(a,x,sizeof(a))
#define rep(i,l,r) for(int i=l;i<r;i++)
#define lowbit(a) ((a)&(-(a)))
typedef long long ll;
typedef unsigned long long ul;
using namespace std;
int read(){
    int ans=0,f=1;
    char c=getchar();
    while(!isdigit(c)){
        if(c=='-') f=-1;
        c=getchar();
    }
    while(isdigit(c)){
        ans=ans*10+c-'0';
        c=getchar();
    }
    return ans*f;
}
const int maxn=550000,inf=1e9;
struct node*null;
struct node{
    int v,sum,maxl,maxr,mx,s,set;
    bool rev;
    node*ch[2];
    inline int cmp(int k){
        k-=ch[0]->s;
        if(k==1) return -1;
        return (k<=0)?0:1;
    }
    inline void maintain(){
        s=ch[0]->s+ch[1]->s+1;
        sum=ch[0]->sum+ch[1]->sum+v;
        maxl=max(ch[0]->maxl,ch[0]->sum+v+max(0,ch[1]->maxl));
        maxr=max(ch[1]->maxr,ch[1]->sum+v+max(0,ch[0]->maxr));
        mx=max(ch[0]->mx,ch[1]->mx);
        mx=max(mx,max(0,ch[0]->maxr)+v+max(0,ch[1]->maxl));
    }
    inline void Set(int k){
        set=k;
        v=k;
        sum=s*k;
        mx=maxl=maxr=k*(k>0?s:1);    
    }
    inline void Rev(){
        rev^=1;
        swap(ch[0],ch[1]);
        swap(maxl,maxr);
    }
    inline void pushdown(){
        if(set!=inf){
            if(ch[0]!=null) ch[0]->Set(set);
            if(ch[1]!=null) ch[1]->Set(set);
            set=inf;
            rev=0;
        }
        if(rev){
            rev=0;
            if(ch[0]!=null) ch[0]->Rev();
            if(ch[1]!=null) ch[1]->Rev();
        }
    }
};
int pos,tot,n,m,a[maxn];
node x[maxn],*root;
queue<node*>Q;
node*newnode(int k){
    node*o=Q.front();Q.pop();
    o->ch[0]=o->ch[1]=null;
    o->s=1;
    o->set=inf;
    o->rev=0;
    o->v=o->sum=o->maxl=o->maxr=o->mx=k;
    return o;
}
void rot(node*&o,int d){
    o->pushdown();
    node*k=o->ch[d^1];
    k->pushdown();
    o->ch[d^1]=k->ch[d];
    k->ch[d]=o;
    o->maintain();k->maintain();
    o=k;
}
void splay(node*&o,int k){
    o->pushdown();
    int d=o->cmp(k);
    if(d==-1) return;
    if(d==1) k-=o->ch[0]->s+1;
    node*p=o->ch[d];
    p->pushdown();
    int d1=p->cmp(k);
    int k1=(d1)?k-p->ch[0]->s-1:k; 
    if(d1!=-1){
        splay(p->ch[d1],k1);
        (d==d1)?rot(o,d^1):rot(o->ch[d],d);
    }
    rot(o,d^1);
}
node*build(int l,int r){
    if(l>=r) return null;
    int mid=(l+r)>>1;
    node*o=newnode(a[mid]);
    if(l<mid) o->ch[0]=build(l,mid);
    if(r>mid+1) o->ch[1]=build(mid+1,r);
    o->maintain();
    return o;
}
void ins(){
    node*o=build(1,tot+1);
    splay(root,pos+1);
    splay(root->ch[1],pos+1-root->ch[0]->s);
    root->ch[1]->ch[0]=o;
    root->ch[1]->maintain();root->maintain();
}
void del(node*o){
    if(o==null) return;
    del(o->ch[0]);
    del(o->ch[1]);
     Q.push(o);
}
void init(){
    rep(i,0,maxn) Q.push(x+i);
    null=newnode(0);
    null->s=0;
    null->maxl=null->maxr=null->mx=null->v=-inf; 
    root=build(0,n+2);
}
void dfs(node*o){
    if(o==null) return;
    o->pushdown();
    dfs(o->ch[0]);
    printf("%d ",o->mx);
    dfs(o->ch[1]);
}
int main()
{    
    n=read(),m=read();
    rep(i,1,n+1) a[i]=read();
    a[0]=a[n+1]=-inf;
    init();
    while(m--){
        char c[15];
        scanf(" %s",c);
        if(c[0]=='I'){
            pos=read(),tot=read();
            clr(a,0);
            rep(i,1,tot+1) a[i]=read();
            ins();
        }else if(c[0]=='D'){
            pos=read(),tot=read();
            splay(root,pos);
            splay(root->ch[1],pos+tot-root->ch[0]->s);
            del(root->ch[1]->ch[0]);
            root->ch[1]->ch[0]=null;
            root->ch[1]->maintain();root->maintain();
        }else if(c[0]=='R'){
            pos=read(),tot=read();
            splay(root,pos);
            splay(root->ch[1],pos+tot-root->ch[0]->s);
            root->ch[1]->ch[0]->Rev();
            root->ch[1]->maintain();root->maintain();
        }else if(c[0]=='G'){
            pos=read(),tot=read();
            splay(root,pos);
            splay(root->ch[1],pos+tot-root->ch[0]->s);
            printf("%d\n",root->ch[1]->ch[0]->sum);
        }else if(c[2]=='K'){
            pos=read(),tot=read();
            int t=read();
            splay(root,pos);
            splay(root->ch[1],pos+tot-root->ch[0]->s);
            root->ch[1]->ch[0]->Set(t);
            root->ch[1]->maintain();root->maintain();
        }else{
            printf("%d\n",root->mx);
        }    
    }
    return 0;
}