【模板】可持久化平衡树

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<string>
#include<cmath>
#include<map>
#include<set>
#include<vector>
#include<queue>
#include<bitset>
#include<ctime>
#include<deque>
#include<stack>
#include<functional>
#include<sstream>
//#include<cctype>
//#pragma GCC optimize(2)
using namespace std;
#define maxn 200005
#define inf 0x7fffffff
//#define INF 1e18
#define rdint(x) scanf("%d",&x)
#define rdllt(x) scanf("%lld",&x)
#define rdult(x) scanf("%lu",&x)
#define rdlf(x) scanf("%lf",&x)
#define rdstr(x) scanf("%s",x)
typedef long long  ll;
typedef unsigned long long ull;
typedef unsigned int U;
#define ms(x) memset((x),0,sizeof(x))
const long long int mod = 1e9;
#define Mod 1000000000
#define sq(x) (x)*(x)
#define eps 1e-5
typedef pair<int, int> pii;
#define pi acos(-1.0)
//const int N = 1005;
#define REP(i,n) for(int i=0;i<(n);i++)
typedef pair<int, int> pii;

inline int rd() {
	int x = 0;
	char c = getchar();
	bool f = false;
	while (!isdigit(c)) {
		if (c == ‘-‘) f = true;
		c = getchar();
	}
	while (isdigit(c)) {
		x = (x << 1) + (x << 3) + (c ^ 48);
		c = getchar();
	}
	return f ? -x : x;
}


ll gcd(ll a, ll b) {
	return b == 0 ? a : gcd(b, a%b);
}
int sqr(int x) { return x * x; }



/*ll ans;
ll exgcd(ll a, ll b, ll &x, ll &y) {
	if (!b) {
		x = 1; y = 0; return a;
	}
	ans = exgcd(b, a%b, x, y);
	ll t = x; x = y; y = t - a / b * y;
	return ans;
}
*/

struct node {
	int l, r;
	int siz;
	int rnd;
	int v;
}t[500005*50];
int cnt, rot[500005];
void upd(int k) {
	t[k].siz = t[t[k].l].siz + t[t[k].r].siz + 1;
}

void newnode(int &k, int x) {
	t[k = ++cnt].v = x; t[k].siz = 1; t[k].rnd = rand();
}
int merge(int a, int b) {
	if (!a || !b)return a + b;
	if (t[a].rnd > t[b].rnd) {
		int p = ++cnt; t[p] = t[a];
		t[p].r = merge(t[p].r, b);
		upd(p); return p;
	}
	else {
		int p = ++cnt; t[p] = t[b];
		t[p].l = merge(a, t[p].l);
		upd(p); return p;
	}
}
void split(int now, int  k, int &x, int &y) {
	if (!now)x = y = 0;
	else {
		if (t[now].v <= k) {
			x = ++cnt; t[x] = t[now];
			split(t[x].r, k, t[x].r, y);
			upd(x);
		}
		else {
			y = ++cnt; t[y] = t[now];
			split(t[y].l, k, x, t[y].l);
			upd(y);
		}
	}
}

void del(int &rt, int w) {
	int x = 0, y = 0, z = 0;
	split(rt, w, x, z); split(x, w - 1, x, y);
	y = merge(t[y].l, t[y].r);
	rt = merge(merge(x, y), z);
}

void ins(int &rt, int w) {
	int x = 0, y = 0, z = 0;
	split(rt, w, x, y); newnode(z, w);
	rt = merge(merge(x, z), y);
}

int getval(int k, int w) {
	if (w == t[t[k].l].siz + 1)return t[k].v;
	else if (w <= t[t[k].l].siz)return getval(t[k].l, w);
	else return getval(t[k].r, w - t[t[k].l].siz - 1);
}
int kth(int &rt, int w) {
	int x, y;
	split(rt, w - 1, x, y);
	int ans = t[x].siz + 1;
	rt = merge(x, y);
	return ans;
}

int getpre(int rt, int w) {
	int x, y, k, ans;
	split(rt, w - 1, x, y);
	if (!x)return -inf;
	k = t[x].siz;
	ans = getval(x, k);
	rt = merge(x, y); return ans;
}
int nxt(int rt, int w) {
	int x, y, ans;
	split(rt, w, x, y);
	if (!y)return inf;
	else ans = getval(y, 1);
	rt = merge(x, y); return ans;
}
	
int main()
{
	//ios::sync_with_stdio(0);
	int n, f, w, tm; n = rd();
	for (int i = 1; i <= n; i++) {
		tm = rd(); f = rd(); w = rd();
		rot[i] = rot[tm];
		if (f == 1)ins(rot[i], w);
		else if (f == 2)del(rot[i], w);
		else if (f == 3)printf("%d\n", kth(rot[i], w));
		else if (f == 4)printf("%d\n", getval(rot[i], w));
		else if (f == 5)printf("%d\n", getpre(rot[i], w));
		else printf("%d\n", nxt(rot[i], w));
	}
	return 0;
}