splay 30pts求助，直接复制p3369的ac代码改一改都不行，枯了

#include<bits/stdc++.h>
using namespace std;
const int N= 2e6+9;
const int INF = 2e9+5;
int root,idx;
int n,m;
int li,ri;

struct node
{
    int s[2];
    int v,p,siz,cnt;
    void init(int _p,int _v)
    {
        p= _p;
        v= _v;
        siz= 1;
        cnt= 1;
    }
}tr[N];

template <typename T> void read(T &x)
{
    x= 0; bool f=1;
    char ch= getchar();
    while (ch<'0'|| ch > '9'){if(ch=='-')f=0; ch= getchar();}
    while (ch>='0'&&ch<='9'){x= (x<<1)+ (x<<3)+ ch - '0'; ch=  getchar();}
    if(!f)x*=-1;
}

void up(int p)
{
    tr[p].siz= tr[tr[p].s[1]].siz+ tr[tr[p].s[0]].siz +tr[p].cnt;
}

void spin(int x)
{
    int y= tr[x].p;
    int z= tr[y].p;
    int k= tr[y].s[1]==x;
    tr[z].s[tr[z].s[1]==y] =x; tr[x].p= z;
    tr[tr[x].s[k^1]].p= y; tr[y].s[k]= tr[x].s[k^1];
    tr[x].s[k^1]= y; tr[y].p= x;
    up(y); up(x);
}

void splay(int x,int k)
{
    while (tr[x].p!=k)
    {
        int y= tr[x].p;
        int z= tr[y].p;
        if(z!=k)
        {
            if((tr[y].s[1]==x) ^ (tr[z].s[1]==y))spin(x);
            else spin(y);
        }
        spin(x);
    }
    if(!k)root= x;
}

void istop(int val)
{
    int u= root;
    if(!u)return ;
    while(tr[u].v!=val && tr[u].s[val> tr[u].v]) u= tr[u].s[val > tr[u].v];

    splay(u,0);
}

void plug(int val)
{
    int u= root; int p =0;
    while (u && tr[u].v!=val) p=u, u= tr[u].s[val>tr[u].v];
    if(u)tr[u].cnt++;
    else
    {
        u= ++idx;
        if(p)tr[p].s [val> tr[p].v] = u;
        tr[u].init(p,val);
    }
    splay(u,0);
}

int getnxt(int val,int jud)
{
    istop(val);
    int u= root;
    if(tr[u].v > val && jud) return u;
    if(tr[u].v < val && !jud) return u;
    u= tr[u].s[jud];
    while (tr[u].s[jud ^ 1])u= tr[u]. s[jud ^ 1];
    return u;
}

int get_v_byk(int x)
{
    int u= root;
    while (tr[u].siz< x)return 0;
    while(1)
    {
       int ls =tr[u].s[0];
       if(x >  tr[ls].siz+ tr[u].cnt)
       {
           x-= tr[ls].siz+ tr[u].cnt;
           u= tr[u].s[1];
       }
       else if(tr[ls].siz>=x) u= ls;
       else return tr[u].v;
    }
    return -1;
}

int get_k_byv(int val)
{
    istop(val);
    return tr[tr[root].s[0]].siz;
}

void del(int val)
{
    int pre = getnxt (val,0);
    int nxt = getnxt (val,1);
    splay (pre ,0); splay(nxt,pre);
    int dtar = tr[nxt].s[0];

    if(tr[dtar].cnt>1)
    {
        tr[dtar].cnt--;
        splay(dtar,0);
    }
    else tr[nxt].s[0]= 0;
}

signed main()
{
    read(n);
    read(m);

    int res= 0;
    int last = 0;
    plug(-INF);
    plug(INF);
    for(int i= 1;i<=n;i++)read(last),plug(last);
    last = 0;
    for(int i= 1;i<=m;i++)
    {
        int op,x;
        read(op);
        read(x);
        x^= last;
        if(op==1) plug(x);
        else if(op==2)del(x);
        else if(op==3)last = get_k_byv(x)+1, res ^= last ;//printf("%d\n",get_k_byv(x));
        else if(op==4)last = get_v_byk(x+1), res ^= last ;//printf("%d\n",get_v_byk(x+1));
        else if(op==5)last = tr[getnxt(x,0)].v, res ^= last ;//printf("%d\n",tr[getnxt(x,0)].v);
        else last = tr[getnxt(x,1)].v, res ^= last ;//printf("%d\n",tr[getnxt(x,1)].v);
    }
    printf("%d\n",res);
    return 0;
}