This documentation is automatically generated by online-judge-tools/verification-helper
#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/courses/lesson/8/ITP2/1/ITP2_1_A"
#include "../../data_structure/splay_tree.hpp"
#include <bits/stdc++.h>
using namespace std;
int main() {
int q;
cin >> q;
splay_tree<ll> st;
while (q--) {
ll ord, x;
cin >> ord;
if (ord == 0) {
cin >> x;
st.insert(st.size(), x);
}
if (ord == 1) {
cin >> x;
cout << st[x] << endl;
}
if (ord == 2) st.erase(st.size() - 1);
}
}
#line 1 "test/onlinejudge.u-aizu.ac.jp/Vector.0.test.cpp"
#define PROBLEM "https://onlinejudge.u-aizu.ac.jp/courses/lesson/8/ITP2/1/ITP2_1_A"
#line 2 "data_structure/splay_tree.hpp"
#line 2 "template.hpp"
#include <bits/stdc++.h>
using namespace std;
#define all(a) begin(a), end(a)
#define rall(a) rbegin(a), rend(a)
#define uniq(a) (a).erase(unique(all(a)), (a).end())
#define t0 first
#define t1 second
using ll = long long;
using ull = unsigned long long;
using pll = pair<ll, ll>;
using vll = vector<ll>;
constexpr double pi = 3.14159265358979323846;
constexpr ll dy[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0};
constexpr ll dx[9] = {1, 0, -1, 0, 1, -1, -1, 1, 0};
constexpr ll sign(ll a) { return (a > 0) - (a < 0); }
constexpr ll fdiv(ll a, ll b) { return a / b - ((a ^ b) < 0 && a % b); }
constexpr ll cdiv(ll a, ll b) { return -fdiv(-a, b); }
constexpr ll pw(ll n) { return 1ll << n; }
constexpr ll flg(ll n) { return 63 - __builtin_clzll(n); }
constexpr ll clg(ll n) { return n == 1 ? 0 : flg(n - 1) + 1; }
constexpr ll safemod(ll x, ll mod) { return (x % mod + mod) % mod; }
template <typename T> using priority_queue_rev = priority_queue<T, vector<T>, greater<T>>;
template <typename T> constexpr T sq(const T &a) { return a * a; }
template <typename T, typename U> constexpr bool chmax(T &a, const U &b) { return a < b ? a = b, true : false; }
template <typename T, typename U> constexpr bool chmin(T &a, const U &b) { return a > b ? a = b, true : false; }
template <typename T, typename U> ostream &operator<<(ostream &os, const pair<T, U> &a) {
os << "(" << a.first << ", " << a.second << ")";
return os;
}
template <typename T, typename U, typename V> ostream &operator<<(ostream &os, const tuple<T, U, V> &a) {
os << "(" << get<0>(a) << ", " << get<1>(a) << ", " << get<2>(a) << ")";
return os;
}
template <typename T> ostream &operator<<(ostream &os, const vector<T> &a) {
os << "(";
for (auto itr = a.begin(); itr != a.end(); ++itr) os << *itr << (next(itr) != a.end() ? ", " : "");
os << ")";
return os;
}
template <typename T> ostream &operator<<(ostream &os, const set<T> &a) {
os << "(";
for (auto itr = a.begin(); itr != a.end(); ++itr) os << *itr << (next(itr) != a.end() ? ", " : "");
os << ")";
return os;
}
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &a) {
os << "(";
for (auto itr = a.begin(); itr != a.end(); ++itr) os << *itr << (next(itr) != a.end() ? ", " : "");
os << ")";
return os;
}
template <typename T, typename U> ostream &operator<<(ostream &os, const map<T, U> &a) {
os << "(";
for (auto itr = a.begin(); itr != a.end(); ++itr) os << *itr << (next(itr) != a.end() ? ", " : "");
os << ")";
return os;
}
#ifdef ONLINE_JUDGE
#define dump(...) (void(0))
#else
void debug() { cerr << endl; }
template <typename Head, typename... Tail> void debug(Head &&head, Tail &&... tail) {
cerr << head;
if (sizeof...(Tail)) cerr << ", ";
debug(tail...);
}
#define dump(...) cerr << __LINE__ << ": " << #__VA_ARGS__ << " = ", debug(__VA_ARGS__)
#endif
struct rep {
struct itr {
ll v;
itr(ll v) : v(v) {}
void operator++() { ++v; }
ll operator*() const { return v; }
bool operator!=(itr i) const { return v < *i; }
};
ll l, r;
rep(ll l, ll r) : l(l), r(r) {}
rep(ll r) : rep(0, r) {}
itr begin() const { return l; };
itr end() const { return r; };
};
struct per {
struct itr {
ll v;
itr(ll v) : v(v) {}
void operator++() { --v; }
ll operator*() const { return v; }
bool operator!=(itr i) const { return v > *i; }
};
ll l, r;
per(ll l, ll r) : l(l), r(r) {}
per(ll r) : per(0, r) {}
itr begin() const { return r - 1; };
itr end() const { return l - 1; };
};
struct io_setup {
static constexpr int PREC = 20;
io_setup() {
cout << fixed << setprecision(PREC);
cerr << fixed << setprecision(PREC);
};
} iOS;
#line 4 "data_structure/splay_tree.hpp"
template <typename V> struct splay_tree {
struct node {
node *left, *right, *par;
ll size;
V val;
node(V val) : left(nullptr), right(nullptr), par(nullptr), size(1), val(val) {}
void rotate() {
node *p, *pp, *c;
p = par, pp = p->par;
if (p->left == this) {
c = right, right = p, p->left = c;
} else {
c = left, left = p, p->right = c;
}
if (pp) {
if (pp->left == p) {
pp->left = this;
} else {
pp->right = this;
}
}
if (c) c->par = p;
par = pp, p->par = this;
p->update();
update();
}
ll state() {
if (!par) { return 0; }
if (par->left == this) {
return 1;
} else {
return -1;
}
}
void splay() {
while (state() != 0) {
if (par->state() == 0) {
rotate();
} else if (state() == par->state()) {
par->rotate(), rotate();
} else {
rotate(), rotate();
}
}
}
void update() {
size = 1;
if (left) size += left->size;
if (right) size += right->size;
}
};
node *root;
splay_tree(node *root = nullptr) : root(root) {}
ll size() { return root ? root->size : 0; }
node *get_node(ll i) {
node *cur = root;
while (true) {
ll size_l = cur->left ? cur->left->size : 0;
if (i < size_l) cur = cur->left;
if (i == size_l) {
cur->splay();
return root = cur;
}
if (i > size_l) cur = cur->right, i -= size_l + 1;
}
}
V &operator[](ll i) { return get_node(i)->val; }
template <typename F> ll lower_bound(F f) {
if (!root) return 0;
node *cur = root;
ll ret = -1;
while (true) {
if (cur->state() < 1) {
ret += cur->left ? cur->left->size + 1 : 1;
} else {
ret -= cur->right ? cur->right->size + 1 : 1;
}
if (f(cur->val)) {
if (cur->left) {
cur = cur->left;
} else {
cur->splay(), root = cur;
return ret;
}
} else {
if (cur->right) {
cur = cur->right;
} else {
cur->splay(), root = cur;
return ret + 1;
}
}
}
}
splay_tree split(ll size_left) {
if (size_left == 0) {
node *root_r = root;
root = nullptr;
return root_r;
}
if (size_left == root->size) return nullptr;
node *root_r = get_node(size_left);
root = root_r->left;
root_r->left = nullptr, root->par = nullptr;
root_r->update();
return root_r;
}
void merge(splay_tree right) {
if (!root) {
root = right.root;
return;
}
if (!right.root) return;
get_node(root->size - 1);
root->right = right.root, right.root->par = root;
root->update();
}
void insert(ll i, V val) {
splay_tree vt = new node(val), right = split(i);
merge(vt), merge(right);
}
void erase(ll i) {
splay_tree vt = split(i);
splay_tree right = vt.split(1);
delete vt.root;
merge(right);
}
};
#line 3 "test/onlinejudge.u-aizu.ac.jp/Vector.0.test.cpp"
#line 5 "test/onlinejudge.u-aizu.ac.jp/Vector.0.test.cpp"
using namespace std;
int main() {
int q;
cin >> q;
splay_tree<ll> st;
while (q--) {
ll ord, x;
cin >> ord;
if (ord == 0) {
cin >> x;
st.insert(st.size(), x);
}
if (ord == 1) {
cin >> x;
cout << st[x] << endl;
}
if (ord == 2) st.erase(st.size() - 1);
}
}