結果

問題 No.1975 Zigzag Sequence
ユーザー ___Johniel___Johniel
提出日時 2022-06-12 20:51:46
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 114 ms / 2,000 ms
コード長 4,261 bytes
コンパイル時間 1,971 ms
コンパイル使用メモリ 185,504 KB
実行使用メモリ 20,592 KB
最終ジャッジ日時 2024-09-23 07:40:04
合計ジャッジ時間 6,149 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge4
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 33
権限があれば一括ダウンロードができます

ソースコード

diff # 

// yukicoder/1975/main.cpp
// author: @___Johniel
// github: https://github.com/johniel/

#include <bits/stdc++.h>

#define each(i, c) for (auto& i : c)
#define unless(cond) if (!(cond))
// #define endl "\n"

using namespace std;

template<typename P, typename Q> ostream& operator << (ostream& os, pair<P, Q> p) { os << "(" << p.first << "," << p.second << ")"; return os; }
template<typename P, typename Q> istream& operator >> (istream& is, pair<P, Q>& p) { is >> p.first >> p.second; return is; }
template<typename T> ostream& operator << (ostream& os, vector<T> v) { os << "("; for (auto& i: v) os << i << ","; os << ")"; return os; }
template<typename T> istream& operator >> (istream& is, vector<T>& v) { for (auto& i: v) is >> i; return is; }
template<typename T> ostream& operator << (ostream& os, set<T> s) { os << "#{"; for (auto& i: s) os << i << ","; os << "}"; return os; }
template<typename K, typename V> ostream& operator << (ostream& os, map<K, V> m) { os << "{"; for (auto& i: m) os << i << ","; os << "}"; return os; }
template<typename E, size_t N> istream& operator >> (istream& is, array<E, N>& a) { for (auto& i: a) is >> i; return is; }
template<typename E, size_t N> ostream& operator << (ostream& os, array<E, N>& a) { os << "[]{"; for (auto& i: a) os << i << ","; os << "}"; return os; }

template<typename T> inline T setmax(T& a, T b) { return a = std::max(a, b); }
template<typename T> inline T setmin(T& a, T b) { return a = std::min(a, b); }

using lli = long long int;
using ull = unsigned long long;
using point = complex<double>;
using str = string;
template<typename T> using vec = vector<T>;

constexpr array<int, 8> di({0, 1, -1, 0, 1, -1, 1, -1});
constexpr array<int, 8> dj({1, 0, 0, -1, 1, -1, -1, 1});
constexpr lli mod = 1e9 + 7;
// constexpr lli mod = 998244353;

template<typename T = long long int>
struct BIT {
  vector<T> v;
  int n;

  BIT(int n_ = 0) {
    n = n_;
    v.resize(n + 1, 0);
  }

  T operator () (int i) const {
    T s = 0;
    while (i > 0) {
      (s += v.at(i)) %= mod;
      i -= i & -i;
    }
    return s;
  }

  T operator () (int begin, int end) const {
    assert(begin <= end);
    return (*this)(end) - (*this)(begin);
  }

  void add(int i, T x) {
    ++i;
    while (i <= n) {
      (v.at(i) += x) %= mod;
      i += i & -i;
    }
    return ;
  }

  static bool verify(void) {
    vector<int> v;
    v.push_back(1 << 0);
    v.push_back(1 << 2);
    v.push_back(1 << 1);
    v.push_back(1 << 4);
    v.push_back(1 << 3);
    v.push_back(1 << 6);
    v.push_back(1 << 5);

    BIT<int> bit(v.size());
    for (int i = 0; i < v.size(); ++i) {
      bit.add(i, v[i]);
    }

    if (bit(1, 3) != v[1] + v[2]) return false;

    int sum = 0;
    for (int i = 0; i < v.size(); ++i) {
      if (sum != bit(i)) return false;
      sum += v[i];
    }
    if (sum != bit(v.size())) return false;

    for (int i = 0; i < v.size(); ++i) {
      int sum = 0;
      for (int j = i; j < v.size(); ++j) {
        if (sum != bit(i, j)) return false;
        sum += v[j];
      }
      if (sum != bit(i, v.size())) return false;
    }

    return true;
  }
};

int main(int argc, char *argv[])
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.setf(ios_base::fixed);
  cout.precision(15);

  const int N = 5 * 1e5 + 3;
  static lli w[N];
  w[0] = 1;
  for (int i = 1; i < N; ++i) {
    w[i] = w[i - 1] * 2 % mod;
  }

  int n;
  while (cin >> n) {
    vec<lli> a(n);
    cin >> a;

    vec<lli> b = a;
    sort(b.begin(), b.end());
    b.erase(unique(b.begin(), b.end()), b.end());
    map<lli, int> m;
    for (int i = 0; i < b.size(); ++i) {
      m[b[i]] = i;
    }
    each (i, a) i = m[i];

    lli z = 0;
    for (int _ = 0; _ < 2; ++_) {
      vec<lli> v[2];
      v[0] = v[1] = vec<lli>(a.size(), 0);
      for (int __ = 0; __ < 2; ++__) {
        BIT<lli> bit(N);
        for (int i = 0; i < a.size(); ++i) {
          lli x = bit(0, a[i]);
          v[__][i] = x;
          bit.add(a[i], w[i]);
        }
        reverse(a.begin(), a.end());
      }
      reverse(v[1].begin(), v[1].end());
      for (int i = 0; i < n; ++i) {
        z += v[0][i] * v[1][i] % mod;
        z %= mod;
      }
      each (i, a) i = i * (-1) + m.size();
    }
    cout << z << endl;
  }

  return 0;
}
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