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| #include <bits/stdc++.h>
using namespace std;
#define gc getchar
typedef long long ll;
const int N = 5e5 + 10,inf = 1e9;
ll read()
{
ll a = 0,b = 0;char c = gc();
while(c < '0'||c > '9') b = (c == '-'),c = gc();
while(c >= '0'&&c <= '9') a = a * 10 + c - 48,c = gc();
return b ? -a : a;
}
struct node
{
int val,pri,siz;
int ls,rs;
};
struct pir{int l,r;};
struct treap
{
node tr[N];
int idx = 0;
void upd(int u)
{
if(!u) return ;
node &p = tr[u];
p.siz = tr[p.ls].siz + tr[p.rs].siz + 1;
}
pir split(int rt,int val)
{
if(!rt) return pir{0,0};
node &p = tr[rt];
pir o;
if(p.val < val)
{
o = split(p.rs,val);
p.rs = o.l;
o.l = rt;
}
else
{
o = split(p.ls,val);
p.ls = o.r;
o.r = rt;
}
upd(rt);
return o;
}
int merge(int l,int r)
{
if(!l||!r) return l + r;
node &lp = tr[l],&rp = tr[r];
if(lp.pri < rp.pri)
{
rp.ls = merge(l,rp.ls);
upd(r);
return r;
}
else
{
lp.rs = merge(lp.rs,r);
upd(l);
return l;
}
}
int ins(int rt,int val)
{
pir o = split(rt,val);
tr[++idx] = node{val,rand(),1,0,0};
o.l = merge(o.l,idx);
return merge(o.l,o.r);
}
int del(int rt,int val)
{
node &p = tr[rt];
if(p.val < val) p.rs = del(p.rs,val);
else if(p.val == val)
{
rt = merge(p.ls,p.rs);
upd(rt);
return rt;
}
else p.ls = del(p.ls,val);
upd(rt);
return rt;
}
int find_kth(int rt,int val)
{
if(!rt) return 1;
node p = tr[rt];
if(p.val < val) return find_kth(p.rs,val) + tr[p.ls].siz + 1;
else return find_kth(p.ls,val);
}
int find_val(int rt,int k)
{
if(!rt) return -1;
node p = tr[rt];
if(tr[p.ls].siz + 1 > k) return find_val(p.ls,k);
else if(tr[p.ls].siz + 1 == k) return p.val;
else return find_val(p.rs,k - tr[p.ls].siz - 1);
}
int find_pre(int rt,int val)
{
int pre = -inf;
while(rt)
{
if(tr[rt].val < val) pre = tr[rt].val,rt = tr[rt].rs;
else rt = tr[rt].ls;
}
return pre;
}
int find_suc(int rt,int val)
{
int suc = inf;
while(rt)
{
if(tr[rt].val > val) suc = tr[rt].val,rt = tr[rt].ls;
else rt = tr[rt].rs;
}
return suc;
}
}t;
int main()
{
int T = read(),rt = 0;
while(T--)
{
int op = read(),p = read();
if(op == 1) rt = t.ins(rt,p);
if(op == 2) rt = t.del(rt,p);
if(op == 3) printf("%d\n",t.find_kth(rt,p));
if(op == 4) printf("%d\n",t.find_val(rt,p));
if(op == 5) printf("%d\n",t.find_pre(rt,p));
if(op == 6) printf("%d\n",t.find_suc(rt,p));
}
return 0;
}
|