tests/Deque.test.cpp

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• Last update: 2025-11-28 02:09:51+07:00
• Problem: https://judge.yosupo.jp/problem/deque

Depends on

• misc/macros.h

Code

#define PROBLEM "https://judge.yosupo.jp/problem/deque"

#include "../misc/macros.h"

void solve() {
  int q;
  cin >> q;
  deque<int> dq;
  while (q--) {
    int t;
    cin >> t;
    if (t == 0) {
      int x;
      cin >> x;
      dq.push_front(x);
    } else if (t == 1) {
      int x;
      cin >> x;
      dq.push_back(x);
    } else if (t == 2) {
      dq.pop_front();
    } else if (t == 3) {
      dq.pop_back();
    } else if (t == 4) {
      int i;
      cin >> i;
      cout << dq[i] << '\n';
    }
  }
}

int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);
#ifdef LOCAL
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
  int tc = 1;
  // cin >> tc;
  for (int i = 1; i <= tc; ++i) {
    solve();
  }
}

#line 1 "tests/Deque.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/deque"

#line 1 "misc/macros.h"
// #pragma GCC optimize("Ofast,unroll-loops")       // unroll long, simple loops
// #pragma GCC target("avx2,fma")                   // vectorizing code
// #pragma GCC target("lzcnt,popcnt,abm,bmi,bmi2")  // for fast bitset operation

#include <bits/extc++.h>
#include <tr2/dynamic_bitset>

using namespace std;
using namespace __gnu_pbds;  // ordered_set, gp_hash_table
// using namespace __gnu_cxx; // rope

// for templates to work
#define all(x) (x).begin(), (x).end()
#define sz(x) (int) (x).size()
#define pb push_back
#define eb emplace_back
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
using i128 = __int128_t;
using u128 = __uint128_t;
using ld = long double;
using pii = pair<i32, i32>;
using vi = vector<i32>;

// fast map
const int RANDOM = chrono::high_resolution_clock::now().time_since_epoch().count();
struct chash {  // customize hash function for gp_hash_table
  int operator()(int x) const { return x ^ RANDOM; }
};
gp_hash_table<int, int, chash> table;

/* ordered set
    find_by_order(k): returns an iterator to the k-th element (0-based)
    order_of_key(k): returns the number of elements in the set that are strictly less than k
*/
template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

/*  rope
    rope <int> cur = v.substr(l, r - l + 1);
    v.erase(l, r - l + 1);
    v.insert(v.mutable_begin(), cur);
*/
#line 4 "tests/Deque.test.cpp"

void solve() {
  int q;
  cin >> q;
  deque<int> dq;
  while (q--) {
    int t;
    cin >> t;
    if (t == 0) {
      int x;
      cin >> x;
      dq.push_front(x);
    } else if (t == 1) {
      int x;
      cin >> x;
      dq.push_back(x);
    } else if (t == 2) {
      dq.pop_front();
    } else if (t == 3) {
      dq.pop_back();
    } else if (t == 4) {
      int i;
      cin >> i;
      cout << dq[i] << '\n';
    }
  }
}

int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);
#ifdef LOCAL
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
  int tc = 1;
  // cin >> tc;
  for (int i = 1; i <= tc; ++i) {
    solve();
  }
}

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