結果

問題 No.958 たぷりすたべる (回文)
コンテスト
ユーザー ei1333333
提出日時 2019-12-19 15:54:31
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
WA  
実行時間 -
コード長 5,829 bytes
コンパイル時間 2,459 ms
コンパイル使用メモリ 204,268 KB
最終ジャッジ日時 2025-01-08 12:46:22
ジャッジサーバーID
（参考情報） 		judge5 / judge5
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 WA * 2
other AC * 1 WA * 52
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;

using int64 = long long;
const int mod = 998244353;

const int64 infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;


template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 > &p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for(int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for(T &in : v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for(auto &e : t) fill_v(e, v);
}

template< typename F >
struct FixPoint : F {
  FixPoint(F &&f) : F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};

template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}

vector< int > manacher(const string &s) {
  vector< int > radius(s.size());
  int i = 0, j = 0;
  while(i < s.size()) {
    while(i - j >= 0 && i + j < s.size() && s[i - j] == s[i + j]) {
      ++j;
    }
    radius[i] = j;
    int k = 1;
    while(i - k >= 0 && i + k < s.size() && k + radius[i - k] < j) {
      radius[i + k] = radius[i - k];
      ++k;
    }
    i += k;
    j -= k;
  }
  return radius;
}

template< int mod >
struct ModInt {
  int x;

  ModInt() : x(0) {}

  ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}

  ModInt &operator+=(const ModInt &p) {
    if((x += p.x) >= mod) x -= mod;
    return *this;
  }

  ModInt &operator-=(const ModInt &p) {
    if((x += mod - p.x) >= mod) x -= mod;
    return *this;
  }

  ModInt &operator*=(const ModInt &p) {
    x = (int) (1LL * x * p.x % mod);
    return *this;
  }

  ModInt &operator/=(const ModInt &p) {
    *this *= p.inverse();
    return *this;
  }

  ModInt &operator^=(int64_t n) {
    int y = x;
    x = 1;
    while(n > 0) {
      if(n & 1) x = 1LL * x * y % mod;
      y = 1LL * y * y % mod;
      n >>= 1;
    }
    return *this;
  }

  ModInt operator-() const { return ModInt(-x); }

  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }

  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }

  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }

  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }

  ModInt operator^(const int64_t n) const { return ModInt(*this) ^= n; }

  bool operator==(const ModInt &p) const { return x == p.x; }

  bool operator!=(const ModInt &p) const { return x != p.x; }

  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while(b > 0) {
      t = a / b;
      a -= t * b;
      swap(a, b);
      u -= t * v;
      swap(u, v);
    }
    return ModInt(u);
  }

  friend ostream &operator<<(ostream &os, const ModInt< mod > &p) {
    return os << p.x;
  }

  friend istream &operator>>(istream &is, ModInt< mod > &a) {
    int64_t t;
    is >> t;
    a = ModInt< mod >(t);
    return (is);
  }
};

using modint = ModInt< mod >;

template< typename T >
struct Combination {
  vector< T > _fact, _rfact;

  Combination(int sz) : _fact(sz + 1), _rfact(sz + 1) {
    _fact[0] = _rfact[sz] = 1;
    for(int i = 1; i <= sz; i++) _fact[i] = _fact[i - 1] * i;
    _rfact[sz] /= _fact[sz];
    for(int i = sz - 1; i >= 0; i--) _rfact[i] = _rfact[i + 1] * (i + 1);
  }

  inline T fact(int k) const { return _fact[k]; }

  inline T rfact(int k) const { return _rfact[k]; }

  T P(int n, int r) const {
    if(r < 0 || n < r) return 0;
    return fact(n) * rfact(n - r);
  }

  T C(int p, int q) const {
    if(q < 0 || p < q) return 0;
    return fact(p) * rfact(q) * rfact(p - q);
  }

  T H(int n, int r) const {
    if(n < 0 || r < 0) return (0);
    return r == 0 ? 1 : C(n + r - 1, r);
  }
};

template< typename T >
T lagrange_polynomial(const vector< T > &y, int64_t t) {
  int N = y.size() - 1;
  Combination< T > comb(N);
  if(t <= N) return y[t];
  T ret(0);
  vector< T > dp(N + 1, 1), pd(N + 1, 1);
  for(int i = 0; i < N; i++) dp[i + 1] = dp[i] * (t - i);
  for(int i = N; i > 0; i--) pd[i - 1] = pd[i] * (t - i);
  for(int i = 0; i <= N; i++) {
    T tmp = y[i] * dp[i] * pd[i] * comb.rfact(i) * comb.rfact(N - i);
    if((N - i) & 1) ret -= tmp;
    else ret += tmp;
  }
  return ret;
}

int main() {
  string S;
  cin >> S;
  int K;
  cin >> K;
  int uku = min(K, 10);
  vector< modint > tap;
  string P = "$";
  for(int i = 0; i < 10; i++) {
    for(auto c : S) {
      P += c;
      P += "$";
    }
    auto ret = manacher(P);
    int64 sum = 0;
    for(auto t : ret) sum += t / 2;
    tap.emplace_back(sum);
  }

  cout << lagrange_polynomial< modint >(tap, K - 1) << endl;
}
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