結果

問題 No.3095 Many Min Problems
ユーザー nonon
提出日時 2025-04-06 15:43:56
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 157 ms / 2,000 ms
コード長 18,859 bytes
コンパイル時間 3,261 ms
コンパイル使用メモリ 223,004 KB
実行使用メモリ 14,788 KB
最終ジャッジ日時 2025-04-06 15:44:03
合計ジャッジ時間 6,508 ms
ジャッジサーバーID
(参考情報)
judge2 / judge5
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
sample AC * 3
other AC * 30
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;

#include <atcoder/modint>
using mint = atcoder::modint998244353;

template<typename T>
T gcd(T a, T b) {
	return b == 0 ? a : gcd(a % b, a);
}

namespace combination {

template<typename mint>
struct C {
    static vector<mint> fac, finv;
    static void init(int n) {
        int sz = fac.size();
        if (n < sz) return;
        n = clamp(n, 2 * sz, min(1 << 25, mint::mod() - 1));
        fac.resize(n + 1);
        finv.resize(n + 1);
        for (int i = sz; i <= n; i++) {
            fac[i] = i * fac[i - 1];
        }
        finv[n] = fac[n].inv();
        for (int i = n; i >= sz; i--) {
            finv[i - 1] = i * finv[i];
        }
    }
};
template<typename mint>
vector<mint> C<mint>::fac(1, 1);
template<typename mint>
vector<mint> C<mint>::finv(1, 1);
template<typename mint>
mint fac(int n) {
    C<mint>::init(n);
    if (n < 0) return 0;
    return C<mint>::fac[n];
}
template<typename mint>
mint finv(int n) {
    C<mint>::init(n);
    if (n < 0) return 0;
    return C<mint>::finv[n];
}
template<typename mint>
mint mod_inv(int n) {
    assert(n > 0);
    return finv<mint>(n) * fac<mint>(n - 1);
}
template<typename mint>
mint nCk(int n, int k) {
    if (n < 0 || n < k || k < 0) return 0;
    return fac<mint>(n) * finv<mint>(n - k) * finv<mint>(k);
}
template<typename mint>
mint multi_C(const vector<int> &v) {
    int n = 0;
    for (const int &k : v) n += k;
    mint res = fac<mint>(n);
    for (const int &k : v) res *= finv<mint>(k);
    return res;
}
template<typename mint>
mint nPk(int n, int k) {
    if (n < 0 || n < k || k < 0) return 0;
    return fac<mint>(n) * finv<mint>(n - k);
}
template<typename mint>
mint catalan(int n) {
    return fac<mint>(2 * n) * finv<mint>(n) * finv<mint>(n + 1);
}
template<typename mint>
mint grid_path(int n, int m) {
    return nCk<mint>(n + m, n);
}

} // namespace combination

struct montgomery_modint {
    using int64 = uint64_t;
    using int128 = __uint128_t;
    using modint = montgomery_modint;
    montgomery_modint() : x(0) {}
    montgomery_modint(long long v) : x(reduce((int128(v) + MOD) * R)) {}
    static void set_mod(long long _m) {
        MOD = _m;
        R = -int128(MOD) % MOD;
        INV = get_inv_mod(); 
    }
    static long long mod() { return MOD; }
    long long val() const {
        int64 res = reduce(x);
        return res >= MOD ? res - MOD : res;
    }
    modint& operator+=(const modint &r) {
        x += r.x;
        if (x >= (MOD << 1)) x -= (MOD << 1);
        return *this;
    }
    modint& operator-=(const modint &r) {
        x += (MOD << 1) - r.x;
        if (x >= (MOD << 1)) x -= (MOD << 1);
        return *this;
    }
    modint& operator*=(const modint &r) {
        x = reduce(int128(x) * r.x);
        return *this;
    }
    modint& operator/=(const modint &r) {
        *this *= r.inv();
        return *this;
    }
    friend modint operator+(const modint &a, const modint &b) {
        return modint(a) += b;
    }
    friend modint operator-(const modint &a, const modint &b) {
        return modint(a) -= b;
    }
    friend modint operator*(const modint &a, const modint &b) {
        return modint(a) *= b;
    }
    friend modint operator/(const modint &a, const modint &b) {
        return modint(a) /= b;
    }
    friend bool operator==(const modint &a, const modint &b) {
        return a.val() == b.val();
    }
    friend bool operator!=(const modint &a, const modint &b) {
        return a.val() != b.val();
    }
    modint operator+() const { return *this; }
    modint operator-() const { return modint() - *this; }
    modint inv() const { return pow(MOD - 2); }
    modint pow(int128 k) const {
        modint a = *this;
        modint res = 1;
        while (k > 0) {
            if (k & 1) res *= a;
            a *= a;
            k >>= 1;
        }
        return res;
    }
private:
    int64 x;
    static int64 MOD, INV, R;
    static int64 get_inv_mod() {
        int64 res = MOD;
        for (int t = 0; t < 5; t++) res *= 2 - MOD * res;
        return res;
    }
    static int64 reduce(const int128 &v) {
        return (v + int128(int64(v) * int64(-INV)) * MOD) >> 64;
    }
};
typename montgomery_modint::int64
montgomery_modint::MOD, montgomery_modint::INV, montgomery_modint::R;

bool miller_rabin(long long m, const vector<long long> ps) {
    using mint = montgomery_modint;
    mint::set_mod(m);
    long long u = 0, v = m - 1;
    while ((v & 1) == 0) u++, v >>= 1;
    for (long long p : ps) {
        if (m <= p) return true;
        mint x = mint(p).pow(v);
        if (x != 1) {
            long long w;
            for (w = 0; w < u; w++) {
                if (x == m - 1) break;
                x *= x;
            }
            if (u == w) return false;
        }
    }
    return true;
}

bool miller_rabin_small(long long m) {
    return miller_rabin(m, {2, 7, 61});
}

bool miller_rabin_large(long long m) {
    return miller_rabin(m, {2, 325, 9375, 28178, 450775, 9780504, 1795265022});
}

bool is_prime(long long m) {
    if (m <= 1) return false;
    if (m == 2) return true;
    if (m % 2 == 0) return false;
    return m < 4759123141LL ? miller_rabin_small(m) : miller_rabin_large(m);
}

random_device seed;
mt19937 rng(seed());
mt19937_64 rng_64(seed());

int randint(int low, int hi) {
    assert(low <= hi);
    uniform_int_distribution<int> dist(low, hi);
    return dist(rng);
}

long long randint_64(long long low, long long hi) {
    assert(low <= hi);
    uniform_int_distribution<long long> dist(low, hi);
    return dist(rng_64);
}

double randdouble(double low, double hi) {
    uniform_real_distribution<double> dist(low, hi);
    return dist(rng);
}

pair<int, int> randpair(int low, int hi, bool strict = false) {
    assert(low + strict <= hi);
    int L = randint(low, hi - strict);
    int R = randint(L + strict, hi);
    return make_pair(L, R);
}

pair<long long, long long> randpair_64(long long low, long long hi, bool strict = false) {
    assert(low + strict <= hi);
    long long L = randint_64(low, hi - strict);
    long long R = randint_64(L + strict, hi);
    return make_pair(L, R);
}

template<typename T>
T rho(T n) {
    for (int p : {2, 3, 5, 7}) {
        if (n % p == 0) return p;
    }
    using mint = montgomery_modint;
    mint::set_mod(n);
    while (true) {
        mint u = randint_64(2, n - 1);
        mint v = u;
        mint c = randint_64(1, n - 1);
        T d = 1;
        while (d == 1) {
            u = u * u + c;
            v = v * v + c;
            v = v * v + c;
            d = gcd((u - v).val(), n);
        }
        if (d < n) return d;
    }
    return -1;
}

template<typename T>
vector<T> prime_factor(T n) {
    if (n <= 1) return {};
    if (is_prime(n)) return {n};
    vector<T> res;
    T d = rho(n);
    auto a = prime_factor(d);
    auto b = prime_factor(n / d);
    merge(a.begin(), a.end(), b.begin(), b.end(), back_inserter(res));
    res.erase(unique(res.begin(), res.end()), res.end());
    return res;
}

long long primitive_root(long long m) {
    if (m == 2) return 1;
    if (m == 167772161) return 3;
    if (m == 469762049) return 3;
    if (m == 754974721) return 11;
    if (m == 998244353) return 3;
    if (m == 1224736769) return 3;
    auto ps = prime_factor(m - 1);
    using mint = montgomery_modint;
    mint::set_mod(m);
    mint a = randint_64(1, m - 1);
    while ([&]{
        for (auto p : ps) {
            if (a.pow((m - 1) / p) == 1) return true;
        }
        return false;
    }()) a = randint_64(1, m - 1);
    return a.val();
}

template<typename mint>
struct Number_Theoretic_Transform {
    static vector<mint> dw, dw_inv;
    static int log;
    static mint root;
    static void ntt(vector<mint> &f) {
        init();
        int n = f.size();
        for (int m = n; m >>= 1;) {
            mint w = 1;
            for (int s = 0, k = 0; s < n; s += (m << 1)) {
                for (int i = s, j = s + m; i < s + m; i++, j++) {
                    mint a = f[i], b = f[j] * w;
                    f[i] = a + b;
                    f[j] = a - b;
                }
                w *= dw[__builtin_ctz(++k)];
            }
        }
    }
    static void intt(vector<mint> &f) {
        init();
        int n = f.size();
        for (int m = 1; m < n; m <<= 1) {
            mint w = 1;
            for (int s = 0, k = 0; s < n; s += (m << 1)) {
                for (int i = s, j = s + m; i < s + m; i++, j++) {
                    mint a = f[i], b = f[j];
                    f[i] = a + b;
                    f[j] = (a - b) * w;
                }
                w *= dw_inv[__builtin_ctz(++k)];
            }
        }
        mint invn = mint(n).inv();
        for (mint &x : f) x *= invn;
    }
private:
    Number_Theoretic_Transform() = default;
    static void init() {
        if (log > 0) return;
        int mod = mint::mod();
        root = primitive_root(mod);
        int tmp = mod - 1;
        log = 1;
        while (tmp % 2 == 0) {
            tmp >>= 1;
            log++;
        }
        dw.resize(log);
        dw_inv.resize(log);
        for (int i = 0; i < log; i++) {
            dw[i] = -root.pow((mod - 1) >> (i + 2));
            dw_inv[i] = dw[i].inv();
        }
    }
};
template<typename mint>
vector<mint>Number_Theoretic_Transform<mint>::dw = vector<mint>();
template<typename mint>
vector<mint>Number_Theoretic_Transform<mint>::dw_inv = vector<mint>();
template<typename mint>
int Number_Theoretic_Transform<mint>::log = 0;
template<typename mint>
mint Number_Theoretic_Transform<mint>::root = -1;

template<typename mint>
struct Formal_Power_Series : vector<mint> {
    using FPS = Formal_Power_Series;
    using vector<mint>::vector;
    using NTT = Number_Theoretic_Transform<mint>;
    void ntt() { NTT::ntt(*this); }
    void intt() { NTT::intt(*this); }
    FPS &operator+=(const mint &r) {
        if (this->empty()) this->resize(1);
        (*this)[0] += r;
        return *this;
    }
    FPS &operator-=(const mint &r) {
        if (this->empty()) this->resize(1);
        (*this)[0] -= r;
        return *this;
    }
    FPS &operator*=(const mint &r) {
        for (mint &x : *this) x *= r;
        return *this;
    }
    FPS &operator/=(const mint &r) {
        mint invr = r.inv();
        return *this *= invr;
    }
    FPS &operator+=(const FPS &f) {
        int n = this->size(), m = f.size();
        if (n < m) this->resize(m);
        for (int i = 0; i < m; i++) (*this)[i] += f[i];
        return *this;
    }
    FPS &operator-=(const FPS &f) {
        int n = this->size(), m = f.size();
        if (n < m) this->resize(m);
        for (int i = 0; i < m; i++) (*this)[i] -= f[i];
        return *this;
    }
    FPS &operator*=(const FPS &f) {
        *this = convolution(*this, f);
        return *this;
    }
    FPS &operator/=(const FPS &f) {
        return *this *= f.inv();
    }
    FPS &operator%=(const FPS &f) {
        *this -= div(f) * f;
        this->shrink();
        return *this;
    }
    FPS div(const FPS &f) const {
        if (this->size() < f.size()) return FPS{};
        int n = this->size() - f.size() + 1;
        return (rev().pre(n) * f.rev().inv(n)).pre(n).rev(n);
    }
    FPS operator+(const mint &r) const { return FPS(*this) += r; }
    FPS operator-(const mint &r) const { return FPS(*this) -= r; }
    FPS operator*(const mint &r) const { return FPS(*this) *= r; }
    FPS operator/(const mint &r) const { return FPS(*this) /= r; }
    FPS operator+(const FPS &f) const { return FPS(*this) += f; }
    FPS operator-(const FPS &f) const { return FPS(*this) -= f; }
    FPS operator*(const FPS &f) const { return FPS(*this) *= f; }
    FPS operator/(const FPS &f) const { return FPS(*this) /= f; }
    FPS operator%(const FPS &f) const { return FPS(*this) %= f; }

    FPS operator-() const {
        return FPS{} - *this;
    }
    FPS operator<<(int n) const {
        FPS res(*this);
        res.insert(res.begin(), n, mint());
        return res;
    }
    FPS operator>>(int n) const {
        if (int(this->size()) <= n) return FPS{};
        FPS res(*this);
        res.erase(res.begin(), res.begin() + n);
        return res;
    }
    FPS &operator<<=(int n) {
        return *this = (*this) << n;
    }
    FPS &operator>>=(int n) {
        return *this = (*this) >> n;
    }
    FPS pre(int n) const {
        n = min(n, int(this->size()));
        return FPS(this->begin(), this->begin() + n);
    }
    FPS rev(int deg = -1) const {
        FPS res(*this);
        if (deg != -1) res.resize(deg, 0);
        reverse(res.begin(), res.end());
        return res;
    }
    FPS dot(const FPS &f) const {
        int n = min(this->size(), f.size());
        FPS res(n);
        for (int i = 0; i < n; i++) res[i] = (*this)[i] * f[i];
        return res;
    }
    void shrink() {
        while (this->size() && this->back() == 0) {
            this->pop_back();
        }
    }
    mint operator()(const mint &x) const {
        mint res = 0, powx = 1;
        for (const mint &a : *this) {
            res += a * powx;
            powx *= x;
        }
        return res;
    }
    FPS diff() const {
        int n = this->size();
        if (n == 0) return FPS{};
        FPS res(n - 1);
        for (int i = 1; i < n; i++) {
            res[i - 1] = i * (*this)[i];
        }
        return res;
    }
    FPS integral() const {
        int n = this->size();
        FPS res(n + 1);
        res[0] = 0;
        for (int i = 0; i < n; i++) {
            res[i + 1] = (*this)[i] * combination::mod_inv<mint>(i + 1);
        }
        return res;
    }
    FPS inv(int deg = -1) const {
        int n = this->size();
        assert(n > 0);
        mint c = (*this)[0];
        assert(c != 0);
        if (deg == -1) deg = n;
        FPS res(deg);
        res[0] = c.inv();
        for (int d = 1; d < deg; d <<= 1) {
            FPS f(d << 1), g(d << 1);
            for (int i = 0; i < n && i < d << 1; i++) f[i] = (*this)[i];
            for (int i = 0; i < d; i++) g[i] = res[i];
            f.ntt();
            g.ntt();
            f = f.dot(g);
            f.intt();
            for (int i = 0; i < d; i++) f[i] = 0;
            f.ntt();
            f = f.dot(g);
            f.intt();
            for (int i = d; i < deg && i < d << 1; i++) res[i] -= f[i];
        }
        return res;
    }
    FPS exp(int deg = -1) const {
        int n = this->size();
        if (deg == -1) deg = n;
        if (n == 0) {
            FPS res(deg);
            res[0] = 1;
            return res;
        }
        assert((*this)[0] == 0);
        auto inplace_diff = [](FPS &f) -> void {
            if (f.empty()) return;
            f.erase(f.begin());
            for (int i = 0; i < int(f.size()); i++) f[i] *= i + 1;
        };
        auto inplace_integral = [&](FPS &f) -> void {
            f.insert(f.begin(), 0);
            for (int i = 1; i < int(f.size()); i++) f[i] *= combination::mod_inv<mint>(i);
        };
        FPS b = {1, 1 < n ? (*this)[1] : 0};
        FPS c = {1}, z1, z2 = {1, 1};
        for (int d = 2; d < deg; d <<= 1) {
            FPS  y = b;
            y.resize(d << 1);
            y.ntt();
            z1 = z2;
            FPS z = y.dot(z1);
            z.intt();
            fill(z.begin(), z.begin() + (d >> 1), 0);
            z.ntt();
            z = z.dot(-z1);
            z.intt();
            c.insert(c.end(), z.begin() + (d >> 1), z.end());
            z2 = c;
            z2.resize(d << 1);
            z2.ntt();
            FPS x(this->begin(), this->begin() + min(n, d));
            inplace_diff(x);
            x.push_back(0);
            x.ntt();
            x = x.dot(y);
            x.intt();
            x -= b.diff();
            x.resize(d << 1);
            for (int i = 0; i < d - 1; i++) x[i + d] = x[i], x[i] = 0;
            x.ntt();
            x = x.dot(z2);
            x.intt();
            x.pop_back();
            inplace_integral(x);
            for (int i = d; i < min(n, d << 1); i++) x[i] += (*this)[i];
            fill(x.begin(), x.begin() + d, 0);
            x.ntt();
            x = x.dot(y);
            x.intt();
            b.insert(b.end(), x.begin() + d, x.end());
        }
        return FPS(b.begin(), b.begin() + deg);
    }
    FPS log(int deg = -1) const {
        assert((*this)[0] == 1);
        if (deg == -1) deg = this->size();
        return (diff() * inv()).integral().pre(deg);
    }
    FPS pow(long long k, int deg = -1) const {
        if (deg == -1) deg = this->size();
        if (k == 0) {
            FPS res(deg);
            res[0] = 1;
            return res;
        }
        FPS res(*this);
        int p = 0;
        while (p < int(res.size()) && res[p] == 0) p++;
        if (p > (deg - 1) / k) return FPS(deg);
        res >>= p;
        deg -= p * k;
        mint c = res[0];
        res = ((res / c).log(deg) * k).exp(deg) * c.pow(k);
        res <<= p * k;
        return res;
    }
    FPS taylor_shift(mint c) const {
        int n = this->size();
        FPS f = *this;
        for (int i = 0; i < n; i++) f[i] *= combination::fac<mint>(i);
        reverse(f.begin(), f.end());
        FPS g(n);
        mint pw = 1;
        for (int i = 0; i < n; i++) {
            g[i] = pw * combination::finv<mint>(i);
            pw *= c;
        }
        f = convolution(f, g, n);
        reverse(f.begin(), f.end());
        for (int i = 0; i < n; i++) f[i] *= combination::finv<mint>(i);
        return f;
    }
private:
    static FPS convolution(FPS f, FPS g, int deg = -1) {
        int n = f.size(), m = g.size();
        if (n == 0 || m == 0) return FPS{};
        int sz = 1;
        while (sz < n + m - 1) sz <<= 1;
        f.resize(sz);
        f.ntt();
        g.resize(sz);
        g.ntt();
        f = f.dot(g);
        f.intt();
        if (deg == -1) deg = n + m - 1;
        f.resize(deg);
        return f;
    }
};

template<typename mint>
vector<mint> power_sum(int k, long long n) {
    using FPS = Formal_Power_Series<mint>;
    vector<mint> fac(k + 2), finv(k + 2);
    fac[0] = 1;
    for (int i = 1; i <= k + 1; i++) {
        fac[i] = i * fac[i - 1];
    }
    finv[k + 1] = fac[k + 1].inv();
    for (int i = k + 1; i >= 1; i--) {
        finv[i - 1] = i * finv[i];
    }
    mint pown = n + 1;
    FPS f(k + 1), g(k + 1);
    for (int i = 0; i <= k; i++) {
        f[i] = pown * finv[i + 1];
        g[i] = finv[i + 1];
        pown *= n + 1;
    }
    f /= g;
    vector<mint> res(k + 1);
    res[0] = n + 1;
    for (int i = 1; i <= k; i++) {
        res[i] = f[i] * fac[i];
    }
    return res;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, M;
    cin >> N >> M;
    auto P = power_sum<mint>(N, M);
    mint ans = 0;
    for (int i = 1; i <= N; i++) {
        ans += P[i] * mint(M).pow(N - i);
    }
    cout << ans.val() << endl;
}
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