結果

問題 No.1136 Four Points Tour
ユーザー ninoinui
提出日時 2020-12-13 04:09:13
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 113 ms / 2,000 ms
コード長 4,168 bytes
コンパイル時間 2,538 ms
コンパイル使用メモリ 197,616 KB
最終ジャッジ日時 2025-01-16 23:09:51
ジャッジサーバーID
（参考情報） 		judge2 / judge1
このコードへのチャレンジ
（要ログイン）
ファイルパターン 結果
other AC * 22 RE * 18 MLE * 1
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 # 

#include <bits/stdc++.h>
using namespace std;

template <class A, class B> bool cmin(A& a, B b) { return a > b && (a = b, true); }
template <class A, class B> bool cmax(A& a, B b) { return a < b && (a = b, true); }

template <unsigned int mod> class modint {
private:
  unsigned int v;
  static unsigned int norm(const unsigned int& x) { return x < mod ? x : x - mod; }
  static modint make(const unsigned int& x) {
    modint m;
    return m.v = x, m;
  }
  static modint inv(const modint& x) { return make(inverse(x.v, mod)); }
  static unsigned int inverse(int a, int m) {
    int u[] = {a, 1, 0}, v[] = {m, 0, 1}, t;
    while (*v) {
      t = *u / *v;
      swap(u[0] -= t * v[0], v[0]), swap(u[1] -= t * v[1], v[1]), swap(u[2] -= t * v[2], v[2]);
    }
    return (u[1] % m + m) % m;
  }

public:
  modint() : v{0} {}
  modint(const long val) : v{norm(val % mod + mod)} {}
  modint(const modint<mod>& n) : v{n()} {}
  explicit operator bool() const noexcept { return v != 0; }
  bool operator!() const noexcept { return !static_cast<bool>(*this); }
  modint& operator=(const modint& n) { return v = n(), (*this); }
  modint& operator=(const long val) { return v = norm(val % mod + mod), (*this); }
  modint operator+() const { return *this; }
  modint operator-() const { return v == 0 ? make(0) : make(mod - v); }
  modint operator+(const modint& val) const { return make(norm(v + val())); }
  modint operator-(const modint& val) const { return make(norm(v + mod - val())); }
  modint operator*(const modint& val) const { return make((long)v * val() % mod); }
  modint operator/(const modint& val) const { return *this * inv(val); }
  modint& operator+=(const modint& val) { return *this = *this + val; }
  modint& operator-=(const modint& val) { return *this = *this - val; }
  modint& operator*=(const modint& val) { return *this = *this * val; }
  modint& operator/=(const modint& val) { return *this = *this / val; }
  modint operator+(const long val) const { return modint{v + val}; }
  modint operator-(const long val) const { return modint{v - val}; }
  modint operator*(const long val) const { return modint{(long)(v * (val % mod))}; }
  modint operator/(const long val) const { return modint{(long)v * inv(val)}; }
  modint& operator+=(const long val) { return *this = *this + val; }
  modint& operator-=(const long val) { return *this = *this - val; }
  modint& operator*=(const long val) { return *this = *this * val; }
  modint& operator/=(const long val) { return *this = *this / val; }
  bool operator==(const modint& val) const { return v == val.v; }
  bool operator!=(const modint& val) const { return !(*this == val); }
  bool operator==(const long val) const { return v == norm(val % mod + mod); }
  bool operator!=(const long val) const { return !(*this == val); }
  unsigned int operator()() const { return v; }
  friend modint operator+(const long val, const modint& n) { return n + val; }
  friend modint operator-(const long val, const modint& n) { return modint{val - n()}; }
  friend modint operator*(const long val, const modint& n) { return n * val; }
  friend modint operator/(const long val, const modint& n) { return modint{val} / n; }
  friend bool operator==(const long val, const modint& n) { return n == val; }
  friend bool operator!=(const long val, const modint& n) { return !(val == n); }
  friend istream& operator>>(istream& is, modint& n) {
    unsigned int v;
    return is >> v, n = v, is;
  }
  friend ostream& operator<<(ostream& os, const modint& n) { return (os << n()); }
  friend modint mod_pow(modint x, long n) {
    modint ans = 1;
    while (n) {
      if (n & 1) ans *= x;
      x *= x, n >>= 1;
    }
    return ans;
  }
};

constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
using mint = modint<MOD>;

signed main() {
  cin.tie(nullptr)->sync_with_stdio(false);

  int N;
  cin >> N;

  vector<vector<mint>> DP(N + 1, vector<mint>(4));
  DP.at(0).at(0) = 1;
  for (int i = 0; i < N; i++) {
    for (int j = 0; j < 4; j++) {
      for (int k = 0; k < 4; k++) {
        if (j == k) continue;
        DP.at(i + 1).at(k) += DP.at(i).at(j);
      }
    }
  }
  cout << DP.back().at(0) << '\n';
}
0