学步园

题意：给你一串灯，灯有开的有关的，也有自己的数值，可进行的操作有：在某个灯后添加新的灯、移除某盏灯、把灯打开或关闭、更新灯的值。有若干询问，问某一区间内的灯的公约数，没有则输出-1。主要是数据比较大，操作多，容易TLE

浙大月赛的题目，天真的我都用链表写了。。。然后内存分配搓了一运行就崩溃。后来百度得知是伸展树（从没听过），用数组和链表做的话，可能都有样例会卡时间造成TLE，百度了一个模板，暂时当作模板用，等多做几道伸展树再搞自己的模板

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cctype>
#include<cstring>
using namespace std;

#define MAXN 300005
#define lson x->ch[0]
#define rson x->ch[1]
#define ket (root->ch[1]->ch[0])

int gcd(int a,int b){
    return b?gcd(b,a%b):a;
}
struct Node{
    int val, sz, id, on, G[2];
    Node *ch[2], *pnt;//左右儿子和父亲
    void up(){
        sz = ch[0]->sz + ch[1]->sz + 1;
        G[on] = gcd(val,gcd(ch[0]->G[on],ch[1]->G[on]));
        G[!on] = gcd(ch[0]->G[!on],ch[1]->G[!on]);
    }
};

struct Splaytree{//伸展树结构体类型
    int top;
    Node *root,*null;
    Node node[MAXN];
    void Rotate(Node *x, int c){
        Node *y = x->pnt;
        y->ch[!c] = x->ch[c];
        if (x->ch[c] != null)
            x->ch[c]->pnt = y;
        x->pnt = y->pnt;
        if (y->pnt != null)
            y->pnt->ch[y->pnt->ch[1] == y] = x;
        x->ch[c] = y;
        y->pnt = x;
        y->up();
    }
    void Splay(Node *x, Node *go){//将x伸展到go的儿子位置处
        while (x->pnt != go){
            if(x->pnt->pnt == go)   Rotate(x,x->pnt->ch[0]==x);
            else{
                Node *y = x->pnt,*z = y->pnt;
                int f = z->ch[1] == y;
                if(y->ch[f] == x)   Rotate(y,!f);
                else    Rotate(x,f);
                Rotate(x,!f);
            }
        }
        x->up();
        if(go == null)  root = x;
    }
    void RTO(int k,Node *go){
        Node *x = root;
        while(lson->sz != k){
            if(lson->sz > k)    x = lson;
            else{
                k -= lson->sz + 1;
                x = rson;
            }
        }
        Splay(x,go);
    }
    int a[MAXN],b[MAXN];
    Node *newnode(int val,int on,Node *f){
        Node *x = &node[++top];
        x->id = top;
        x->sz = 1;
        lson = rson = null;
        x->on = on;
        x->val = x->G[on] = val;
        x->G[!on] = 0;
        x->pnt = f;
        return x;
    }
    Node *build(int l,int r,Node *f){
        if(l > r)   return null;
        int mid = (l + r) / 2;
        Node *x = newnode(a[mid],b[mid],f);
        lson = build(l,mid-1,x);
        rson = build(mid+1,r,x);
        x->up();
        return x;
    }
    void init(int n){
        null = &node[0];
        null->sz = null->G[0] = null->G[0] = null->val = 0;
        top = 0;
        root = newnode(0,0,null);
        root->ch[1] = newnode(0,0,root);
        for(int i = 0;i<n;i++)  scanf("%d%d",&a[i],&b[i]);
        ket = build(0,n-1,root->ch[1]);
        root->ch[1]->up();
        root->up();
    }
    void Get(int l,int r){
        RTO(l-1,null);
        RTO(r+1,root);
    }
    void Query(){
        int l,r,on;
        scanf("%d%d%d",&l,&r,&on);
        Get(l,r);
        int ans = ket->G[on];
        if(!ans)    printf("-1\n");
        else    printf("%d\n",ans);
    }
    void Insert(){//插入一个值
        int i,val,on;
        scanf("%d%d%d",&i,&val,&on);
        RTO(i,null);
        RTO(i+1,root);
        ket = newnode(val,on,root->ch[1]);
        root->ch[1]->up();
        root->up();
    }
    void Delete(){//删除一个值
        int i;
        scanf("%d",&i);
        Get(i,i);
        ket = null;
        root->ch[1]->up();
        root->up();
    }
    void RR(){
        int i;
        scanf("%d",&i);
        Get(i,i);
        ket->on ^= 1;
        swap(ket->G[0],ket->G[1]);
        root->ch[1]->up();
        root->up();
    }
    void Modify(){
        int i,v;
        scanf("%d%d",&i,&v);
        Get(i,i);
        ket->val = ket->G[ket->on] = v;
        root->ch[1]->up();
        root->up();
    }
}sp;
int main(){
    int n,q,i;
    while(scanf("%d%d",&n,&q)!=EOF){
        sp.init(n);
        for(i=0;i<q;i++){
            char c[5];
            scanf("%s",c);
            if(c[0] == 'Q')  sp.Query();
            else if(c[0] == 'I')    sp.Insert();
            else if(c[0] == 'D')    sp.Delete();
            else if(c[0] == 'R')    sp.RR();
            else    sp.Modify();
        }
    }
    return 0;
}