結果

問題 No.2383 Naphthol
ユーザー theory_and_me
提出日時 2023-07-14 22:58:01
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 61 ms / 2,000 ms
コード長 5,509 bytes
コンパイル時間 1,712 ms
コンパイル使用メモリ 198,340 KB
最終ジャッジ日時 2025-02-15 14:32:48
ジャッジサーバーID
（参考情報） 		judge4 / judge2
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 * 18
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;

#define REP(i,n) for(ll i=0;i<(ll)n;i++)
#define dump(x)  cerr << "Line " << __LINE__ << ": " <<  #x << " = " << (x) << "\n";
#define spa << " " <<
#define fi first
#define se second
#define ALL(a)  (a).begin(),(a).end()
#define ALLR(a)  (a).rbegin(),(a).rend()

using ld = long double;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;

template<typename T> using V = vector<T>;
template<typename T> using P = pair<T, T>;
template<typename T> vector<T> make_vec(size_t n, T a) { return vector<T>(n, a); }
template<typename... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec(ts...))>(n, make_vec(ts...)); }
template<class S, class T> ostream& operator << (ostream& os, const pair<S, T> v){os << "(" << v.first << ", " << v.second << ")"; return os;}
template<typename T> ostream& operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << ' '; return os; }
template<class T> ostream& operator<<(ostream& os, const vector<vector<T>> &v){ for(auto &e : v){os << e << "\n";} return os;}
struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;

template <class T> void UNIQUE(vector<T> &x) {sort(ALL(x));x.erase(unique(ALL(x)), x.end());}
template<class T> bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T> bool chmin(T &a, const T &b) { if (a>b) { a=b; return 1; } return 0; }
void fail() { cout << -1 << '\n'; exit(0); }
inline int popcount(const int x) { return __builtin_popcount(x); }
inline int popcount(const ll x) { return __builtin_popcountll(x); }
template<typename T> void debug(vector<vector<T>>&v,ll h,ll w){for(ll i=0;i<h;i++)
{cerr<<v[i][0];for(ll j=1;j<w;j++)cerr spa v[i][j];cerr<<"\n";}};
template<typename T> void debug(vector<T>&v,ll n){if(n!=0)cerr<<v[0];
for(ll i=1;i<n;i++)cerr spa v[i];
cerr<<"\n";};

const ll INF = (1ll<<62);
// const ld EPS   = 1e-10;
// const ld PI    = acos(-1.0);
// const ll mod = (int)1e9 + 7;
const ll mod = 998244353;

template <std::uint_fast64_t Modulus> class modint {
  // long long から modint を作るときは必ず正の数にしてからコンストラクタに入れること！ 
  // そうしないとバグります
  using u64 = std::uint_fast64_t;

public:
  u64 a;

  constexpr modint(const u64 x = 0) noexcept : a(x % Modulus) {}
  constexpr u64 &value() noexcept { return a; }
  constexpr const u64 &value() const noexcept { return a; }
  constexpr modint operator+(const modint rhs) const noexcept {
    return modint(*this) += rhs;
  }
  constexpr modint operator-(const modint rhs) const noexcept {
    return modint(*this) -= rhs;
  }
  constexpr modint operator*(const modint rhs) const noexcept {
    return modint(*this) *= rhs;
  }
  constexpr modint operator/(const modint rhs) const noexcept {
    return modint(*this) /= rhs;
  }
  constexpr modint &operator+=(const modint rhs) noexcept {
    a += rhs.a;
    if (a >= Modulus) {
      a -= Modulus;
    }
    return *this;
  }
  constexpr modint &operator-=(const modint rhs) noexcept {
    if (a < rhs.a) {
      a += Modulus;
    }
    a -= rhs.a;
    return *this;
  }
  constexpr modint &operator*=(const modint rhs) noexcept {
    a = a * rhs.a % Modulus;
    return *this;
  }
  constexpr modint &operator/=(modint rhs) noexcept {
    u64 exp = Modulus - 2;
    while (exp) {
      if (exp % 2) {
        *this *= rhs;
      }
      rhs *= rhs;
      exp /= 2;
    }
    return *this;
  }
};
using mint = modint<mod>;
using vm = vector<mint>;
using vvm = vector<vm>;

ostream& operator << (ostream& os, const mint v){
os << v.value(); return os;
}

template <class T, class U> constexpr T power(T x, U exp) {
  T ret = static_cast<T>(1);
  while (exp) {
    if (exp % static_cast<U>(2) == static_cast<U>(1))
      ret *= x;
    exp /= static_cast<U>(2);
    x *= x;
  }
  return ::std::move(ret);
}

int main(){

    // 二項係数
    const int n_max = 300000;
    std::vector<mint> fact(n_max), inv_fact(n_max);
    fact[0] = 1;
    for (int i = 1; i < n_max; ++i) {
        fact[i] = fact[i - 1] * i;
    }
        for (int i = 0; i < n_max; ++i) {
        inv_fact[i] = mint(1)/fact[i];
    }
    const auto comb = [&fact, inv_fact](int n, int r) {
        if(n<r or n<0 or r<0) return mint(0);
        return fact[n] * inv_fact[r] * inv_fact[n - r];
    };
    //

    ll N, K;
    cin >> N >> K;

    if(N == 1){
        mint res = 0;
        if(K == 1) res = 1;
        else if(K == 2) res = 3;
        else if(K == 3) res = 3;
        else if(K == 4) res = 3;
        else if(K == 5) res = 1;
        else if(K == 6) res = 1;
        cout << res << endl;
        return 0;
    }

    vector<mint> x(4, 0);
    x[0] = comb(2 * N + 4, K);
    if(N % 2 == 0){
        if(K % 2 == 0){
            x[1] = comb(N + 2, K / 2);
            x[2] = comb(N + 2, K / 2);
            x[3] = comb(N + 2, K / 2);
        }else{
            x[1] = 0;
            x[2] = 0;
            x[3] = 0;
        }
    }else{
        if(K % 2 == 0){
            x[1] = comb(N + 2, K / 2);
            x[2] = comb(N + 1, K / 2) + comb(N + 1, (K - 2) / 2);
            x[3] = comb(N + 2, K / 2);
        }else{
            x[1] = 0;
            x[2] = comb(N + 1, (K - 1) / 2) * 2;
            x[3] = 0;
        }
    }

    mint res = (x[0] + x[1] + x[2] + x[3]) / 4;
    cout << res << endl;

    return 0;
}
0