test/convolution/Convolution.test.cpp

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Last update: 2023-10-31 00:17:11+09:00
Problem: https://judge.yosupo.jp/problem/convolution_mod

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Code

#define PROBLEM "https://judge.yosupo.jp/problem/convolution_mod"

#include <iostream>


#include "../../convolution/ntt.hpp"

#include "../../modint/modint.hpp"


using mint = ebi::modint998244353;

int main() {
    int n, m;
    std::cin >> n >> m;
    std::vector<mint> a(n), b(m);
    for (int i = 0; i < n; ++i) {
        std::cin >> a[i];
    }
    for (int i = 0; i < m; ++i) {
        std::cin >> b[i];
    }
    auto c = ebi::convolution<mint>(a, b);
    for (int i = 0; i < n + m - 1; ++i) {
        std::cout << c[i] << " ";
    }
    std::cout << '\n';
}

#line 1 "test/convolution/Convolution.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/convolution_mod"

#include <iostream>


#line 2 "convolution/ntt.hpp"

#include <algorithm>
#include <array>
#include <bit>
#include <cassert>
#include <vector>

#line 2 "math/internal_math.hpp"

#line 4 "math/internal_math.hpp"

namespace ebi {

namespace internal {

constexpr int primitive_root_constexpr(int 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 == 880803841) return 26;
    if (m == 924844033) return 5;
    return -1;
}
template <int m> constexpr int primitive_root = primitive_root_constexpr(m);

}  // namespace internal

}  // namespace ebi
#line 2 "modint/base.hpp"

#include <concepts>
#line 5 "modint/base.hpp"
#include <utility>

namespace ebi {

template <class T>
concept Modint = requires(T a, T b) {
    a + b;
    a - b;
    a * b;
    a / b;
    a.inv();
    a.val();
    a.pow(std::declval<long long>());
    T::mod();
};

template <Modint mint> std::istream &operator>>(std::istream &os, mint &a) {
    long long x;
    os >> x;
    a = x;
    return os;
}

template <Modint mint>
std::ostream &operator<<(std::ostream &os, const mint &a) {
    return os << a.val();
}

}  // namespace ebi
#line 11 "convolution/ntt.hpp"

namespace ebi {

namespace internal {

template <Modint mint, int g = internal::primitive_root<mint::mod()>>
struct ntt_info {
    static constexpr int rank2 =
        std::countr_zero((unsigned int)(mint::mod() - 1));

    std::array<mint, rank2 + 1> root, inv_root;

    ntt_info() {
        root[rank2] = mint(g).pow((mint::mod() - 1) >> rank2);
        inv_root[rank2] = root[rank2].inv();
        for (int i = rank2 - 1; i >= 0; i--) {
            root[i] = root[i + 1] * root[i + 1];
            inv_root[i] = inv_root[i + 1] * inv_root[i + 1];
        }
    }
};

template <Modint mint> void butterfly(std::vector<mint>& a) {
    static const ntt_info<mint> info;
    int n = int(a.size());
    int bit_size = std::countr_zero(a.size());
    assert(n == (int)std::bit_ceil(a.size()));

    // bit reverse
    for (int i = 0, j = 1; j < n - 1; j++) {
        for (int k = n >> 1; k > (i ^= k); k >>= 1)
            ;
        if (j < i) {
            std::swap(a[i], a[j]);
        }
    }

    for (int bit = 0; bit < bit_size; bit++) {
        for (int i = 0; i < n / (1 << (bit + 1)); i++) {
            mint zeta1 = 1;
            mint zeta2 = info.root[1];
            for (int j = 0; j < (1 << bit); j++) {
                int idx = i * (1 << (bit + 1)) + j;
                int jdx = idx + (1 << bit);
                mint p1 = a[idx];
                mint p2 = a[jdx];
                a[idx] = p1 + zeta1 * p2;
                a[jdx] = p1 + zeta2 * p2;
                zeta1 *= info.root[bit + 1];
                zeta2 *= info.root[bit + 1];
            }
        }
    }
}

template <Modint mint> void butterfly_inv(std::vector<mint>& a) {
    static const ntt_info<mint> info;
    int n = int(a.size());
    int bit_size = std::countr_zero(a.size());
    assert(n == (int)std::bit_ceil(a.size()));

    // bit reverse
    for (int i = 0, j = 1; j < n - 1; j++) {
        for (int k = n >> 1; k > (i ^= k); k >>= 1)
            ;
        if (j < i) {
            std::swap(a[i], a[j]);
        }
    }

    for (int bit = 0; bit < bit_size; bit++) {
        for (int i = 0; i < n / (1 << (bit + 1)); i++) {
            mint zeta1 = 1;
            mint zeta2 = info.inv_root[1];
            for (int j = 0; j < (1 << bit); j++) {
                int idx = i * (1 << (bit + 1)) + j;
                int jdx = idx + (1 << bit);
                mint p1 = a[idx];
                mint p2 = a[jdx];
                a[idx] = p1 + zeta1 * p2;
                a[jdx] = p1 + zeta2 * p2;
                zeta1 *= info.inv_root[bit + 1];
                zeta2 *= info.inv_root[bit + 1];
            }
        }
    }
    mint inv_n = mint(n).inv();
    for (int i = 0; i < n; i++) {
        a[i] *= inv_n;
    }
}

}  // namespace internal

template <Modint mint>
std::vector<mint> convolution_naive(const std::vector<mint>& f,
                                    const std::vector<mint>& g) {
    if (f.empty() || g.empty()) return {};
    int n = int(f.size()), m = int(g.size());
    std::vector<mint> c(n + m - 1);
    if (n < m) {
        for (int j = 0; j < m; j++) {
            for (int i = 0; i < n; i++) {
                c[i + j] += f[i] * g[j];
            }
        }
    } else {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                c[i + j] += f[i] * g[j];
            }
        }
    }
    return c;
}

template <Modint mint>
std::vector<mint> convolution(const std::vector<mint>& f,
                              const std::vector<mint>& g) {
    if (f.empty() || g.empty()) return {};
    if (std::min(f.size(), g.size()) < 60) return convolution_naive(f, g);
    int n = std::bit_ceil(f.size() + g.size() - 1);
    std::vector<mint> a(n), b(n);
    std::copy(f.begin(), f.end(), a.begin());
    std::copy(g.begin(), g.end(), b.begin());
    internal::butterfly(a);
    internal::butterfly(b);
    for (int i = 0; i < n; i++) {
        a[i] *= b[i];
    }
    internal::butterfly_inv(a);
    a.resize(f.size() + g.size() - 1);
    return a;
}

}  // namespace ebi
#line 2 "modint/modint.hpp"

#line 5 "modint/modint.hpp"

#line 7 "modint/modint.hpp"

namespace ebi {

template <int m> struct static_modint {
  private:
    using modint = static_modint;

  public:
    static constexpr int mod() {
        return m;
    }

    static constexpr modint raw(int v) {
        modint x;
        x._v = v;
        return x;
    }

    constexpr static_modint() : _v(0) {}

    constexpr static_modint(long long v) {
        v %= (long long)umod();
        if (v < 0) v += (long long)umod();
        _v = (unsigned int)v;
    }

    constexpr unsigned int val() const {
        return _v;
    }

    constexpr unsigned int value() const {
        return val();
    }

    constexpr modint &operator++() {
        _v++;
        if (_v == umod()) _v = 0;
        return *this;
    }
    constexpr modint &operator--() {
        if (_v == 0) _v = umod();
        _v--;
        return *this;
    }

    constexpr modint operator++(int) {
        modint res = *this;
        ++*this;
        return res;
    }
    constexpr modint operator--(int) {
        modint res = *this;
        --*this;
        return res;
    }

    constexpr modint &operator+=(const modint &rhs) {
        _v += rhs._v;
        if (_v >= umod()) _v -= umod();
        return *this;
    }
    constexpr modint &operator-=(const modint &rhs) {
        _v -= rhs._v;
        if (_v >= umod()) _v += umod();
        return *this;
    }
    constexpr modint &operator*=(const modint &rhs) {
        unsigned long long x = _v;
        x *= rhs._v;
        _v = (unsigned int)(x % (unsigned long long)umod());
        return *this;
    }
    constexpr modint &operator/=(const modint &rhs) {
        return *this = *this * rhs.inv();
    }

    constexpr modint operator+() const {
        return *this;
    }
    constexpr modint operator-() const {
        return modint() - *this;
    }

    constexpr modint pow(long long n) const {
        assert(0 <= n);
        modint x = *this, res = 1;
        while (n) {
            if (n & 1) res *= x;
            x *= x;
            n >>= 1;
        }
        return res;
    }
    constexpr modint inv() const {
        assert(_v);
        return pow(umod() - 2);
    }

    friend modint operator+(const modint &lhs, const modint &rhs) {
        return modint(lhs) += rhs;
    }
    friend modint operator-(const modint &lhs, const modint &rhs) {
        return modint(lhs) -= rhs;
    }
    friend modint operator*(const modint &lhs, const modint &rhs) {
        return modint(lhs) *= rhs;
    }

    friend modint operator/(const modint &lhs, const modint &rhs) {
        return modint(lhs) /= rhs;
    }
    friend bool operator==(const modint &lhs, const modint &rhs) {
        return lhs.val() == rhs.val();
    }
    friend bool operator!=(const modint &lhs, const modint &rhs) {
        return !(lhs == rhs);
    }

  private:
    unsigned int _v = 0;

    static constexpr unsigned int umod() {
        return m;
    }
};

using modint998244353 = static_modint<998244353>;
using modint1000000007 = static_modint<1000000007>;

}  // namespace ebi
#line 7 "test/convolution/Convolution.test.cpp"

using mint = ebi::modint998244353;

int main() {
    int n, m;
    std::cin >> n >> m;
    std::vector<mint> a(n), b(m);
    for (int i = 0; i < n; ++i) {
        std::cin >> a[i];
    }
    for (int i = 0; i < m; ++i) {
        std::cin >> b[i];
    }
    auto c = ebi::convolution<mint>(a, b);
    for (int i = 0; i < n + m - 1; ++i) {
        std::cout << c[i] << " ";
    }
    std::cout << '\n';
}