線段樹/樹狀數組裸題，用splay寫

splay也是基本操作pushup pushdown

話說我就是找不到全一點的模板，我自己寫又全是bug，導致代碼風格一直變來變去= =

關鍵是建樹和區間操作（區間和，區間翻轉，區間合並這幾個寫法都很難統一）

#include<map>
#include<set>
#include<list>
#include<cmath>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include
 
<cstring>
#include<iostream>
#include<algorithm>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define C 0.5772156649
#define pi acos(-1.0)
#define ll long long
#define mod 1000000007
#define ls l,m,rt<<1
#define
 
 rs m+1,r,rt<<1|1

using namespace std;
using namespace __gnu_cxx;

const double g=10.0,eps=1e-7;
const int N=100000+10,maxn=100000+10,inf=0x3f3f3f;

struct Node{
    Node *ch[2],*fa;
    int id,s,v,add;
    ll sum;
    void pushdown()
    {
        if(add)
        {
            if(ch[0])
            {
                ch[
 
0]->v += add;
                ch[0]->add += add;
                ch[0]->sum += (ll)add*ch[0]->s;
            }
            if(ch[1])
            {
                ch[1]->v += add;
                ch[1]->add += add;
                ch[1]->sum += (ll)add*ch[1]->s;
            }
            add=0;
        }
    }
    void pushup()
    {
        s = ch[0]->s + ch[1]->s + 1;
        sum = v + ch[0]->sum + ch[1]->sum;
    }
};
Node *root,NODE[N],*null=&NODE[0];
int num[N],n,top;
struct SplayTree{
    void Rotate(Node *x,int f)
    {
        Node* y= x->fa;
        y->pushdown();x->pushdown();
        y->ch[!f] = x->ch[f];
        x->ch[f]->fa = y;
        x->fa = y->fa;
        if(x->fa!=null)y->fa->ch[y->fa->ch[1]==y]=x;
        x->ch[f] = y;
        y->fa=x;
        y->pushup();
    }
    void splay(Node* x,Node* goal)//把x splay到goal下面
    {
        x->pushdown();
        while(x->fa!=goal)
        {
            if(x->fa->fa == goal)Rotate(x,x->fa->ch[0]==x);
            else
            {
                Node *y=x->fa,*z=y->fa;
                int f=(z->ch[0]==y);
                y->ch[f]==x ? Rotate(x,!f):Rotate(y,f);
                Rotate(x,f);
            }
        }
        x->pushup();
        if(goal==null)root=x;
    }
    void RTO(int k,Node *goal)//把排名為k的節點splay到goal下面
    {
        Node *x=root;
        x->pushdown();
        while(x->ch[0]->s+1!=k)
        {
            if(k < x->ch[0]->s+1)x=x->ch[0];
            else
            {
                k -= x->ch[0]->s+1;
                x = x->ch[1];
            }
            x->pushdown();
        }
        splay(x,goal);
    }
    Node* newnode(Node* fa,int v)
    {
        Node *x=&NODE[++top];
        x->id=top;
        x->ch[0]=x->ch[1]=null;
        x->s=1;
        x->v=x->sum=v;
        x->add=0;
        x->fa=fa;
        return x;
    }
    void build(Node* &x,int l,int r,Node* fa)
    {
        if(l>r)return ;
        int m=(l+r)>>1;
        x=newnode(fa,num[m]);
        build(x->ch[0],l,m-1,x);
        build(x->ch[1],m+1,r,x);
        x->pushup();
    }
    void debug(Node* x)
    {
        if(x!=null)
        {
            debug(x->ch[0]);
            cout<<x->v<<" "<<x->sum<<endl;
            debug(x->ch[1]);
        }
    }
    void init(int n)
    {
        top=0;
        null->id=0;
        null->fa = null->ch[0] = null->ch[1] = NULL;
        null->s = null->add = null->v = null->sum = 0;
        root = newnode(null,-1);
        root->ch[1] = newnode(root,-1);
        root->s=2;
        for(int i=1;i<=n;i++)scanf("%d",&num[i]);
        build(root->ch[1]->ch[0],1,n,root->ch[1]);
        root->ch[1]->pushup();root->pushup();
    }
    void update()
    {
        int l,r,c;
        scanf("%d%d%d",&l,&r,&c);
        RTO(l,null);
        RTO(r+2,root);
        root->ch[1]->ch[0]->add += c;
        root->ch[1]->ch[0]->v += c;
        root->ch[1]->ch[0]->sum += (ll)c*root->ch[1]->ch[0]->s;
    }
    void query()
    {
        int l,r;
        scanf("%d%d",&l,&r);
        RTO(l,null);
        RTO(r+2,root);
        printf("%lld\n",root->ch[1]->ch[0]->sum);
    }
}spt;
int main()
{
    int n,q;
    scanf("%d%d",&n,&q);
    spt.init(n);
    while(q--)
    {
        char s[2];
        scanf("%s",s);
        if(s[0]==‘Q‘)spt.query();
        else spt.update();
    }
    return 0;
}
/************
10 5
1 5 64 8 2 47 6 4 6 7
************/

POJ3468 splay