Algorithm

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:heavy_check_mark: src/nft_convolution.test.cpp

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Code

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

#include "base.hpp"
#include "util/fast_io.hpp"
#include "bitop.hpp"
#include "math/modint.hpp"
#include "math/nft.hpp"

using Mint = ModInt<998244353>;
template <> const Mint Mint::G = Mint(3);

int main() {
    Scanner sc(stdin);
    Printer pr(stdout);

    int n, m;
    sc.read(n, m);

    V<Mint> a(n);
    for (int i = 0; i < n; i++) {
        sc.read(a[i].v);
    }
    V<Mint> b(m);
    for (int i = 0; i < m; i++) {
        sc.read(b[i].v);
    }
    auto c = multiply(a, b);
    for (auto x : c) {
        pr.write(x.v);
        pr.write(' ');
    }
    pr.writeln();
    return 0;
}
#line 1 "src/nft_convolution.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/convolution_mod"

#line 2 "src/base.hpp"
#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <complex>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <vector>

using namespace std;

using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
constexpr ll TEN(int n) { return (n == 0) ? 1 : 10 * TEN(n - 1); }
template <class T> using V = vector<T>;
template <class T> using VV = V<V<T>>;

#ifdef LOCAL

ostream& operator<<(ostream& os, __int128_t x) {
    if (x < 0) {
        os << "-";
        x *= -1;
    }
    if (x == 0) {
        return os << "0";
    }
    string s;
    while (x) {
        s += char(x % 10 + '0');
        x /= 10;
    }
    reverse(s.begin(), s.end());
    return os << s;
}
ostream& operator<<(ostream& os, __uint128_t x) {
    if (x == 0) {
        return os << "0";
    }
    string s;
    while (x) {
        s += char(x % 10 + '0');
        x /= 10;
    }
    reverse(s.begin(), s.end());
    return os << s;
}

template <class T, class U>
ostream& operator<<(ostream& os, const pair<T, U>& p);
template <class T> ostream& operator<<(ostream& os, const V<T>& v);
template <class T> ostream& operator<<(ostream& os, const deque<T>& v);
template <class T, size_t N>
ostream& operator<<(ostream& os, const array<T, N>& a);
template <class T> ostream& operator<<(ostream& os, const set<T>& s);
template <class T, class U>
ostream& operator<<(ostream& os, const map<T, U>& m);

template <class T, class U>
ostream& operator<<(ostream& os, const pair<T, U>& p) {
    return os << "P(" << p.first << ", " << p.second << ")";
}

template <class T> ostream& operator<<(ostream& os, const V<T>& v) {
    os << "[";
    bool f = false;
    for (auto d : v) {
        if (f) os << ", ";
        f = true;
        os << d;
    }
    return os << "]";
}

template <class T> ostream& operator<<(ostream& os, const deque<T>& v) {
    os << "[";
    bool f = false;
    for (auto d : v) {
        if (f) os << ", ";
        f = true;
        os << d;
    }
    return os << "]";
}
template <class T, size_t N>
ostream& operator<<(ostream& os, const array<T, N>& a) {
    os << "[";
    bool f = false;
    for (auto d : a) {
        if (f) os << ", ";
        f = true;
        os << d;
    }
    return os << "]";
}

template <class T> ostream& operator<<(ostream& os, const set<T>& s) {
    os << "{";
    bool f = false;
    for (auto d : s) {
        if (f) os << ", ";
        f = true;
        os << d;
    }
    return os << "}";
}
template <class T> ostream& operator<<(ostream& os, const multiset<T>& s) {
    os << "{";
    bool f = false;
    for (auto d : s) {
        if (f) os << ", ";
        f = true;
        os << d;
    }
    return os << "}";
}

template <class T, class U>
ostream& operator<<(ostream& os, const map<T, U>& s) {
    os << "{";
    bool f = false;
    for (auto p : s) {
        if (f) os << ", ";
        f = true;
        os << p.first << ": " << p.second;
    }
    return os << "}";
}

struct PrettyOS {
    ostream& os;
    bool first;

    template <class T> auto operator<<(T&& x) {
        if (!first) os << ", ";
        first = false;
        os << x;
        return *this;
    }
};
template <class... T> void dbg0(T&&... t) {
    (PrettyOS{cerr, true} << ... << t);
}
#define dbg(...)                                            \
    do {                                                    \
        cerr << __LINE__ << " : " << #__VA_ARGS__ << " = "; \
        dbg0(__VA_ARGS__);                                  \
        cerr << endl;                                       \
    } while (false);
#else
#define dbg(...)
#endif
#line 2 "src/util/fast_io.hpp"

#include <unistd.h>

struct Scanner {
    int fd = -1;
    char line[(1 << 15) + 1];
    size_t st = 0, ed = 0;
    void reread() {
        memmove(line, line + st, ed - st);
        ed -= st;
        st = 0;
        ed += ::read(fd, line + ed, (1 << 15) - ed);
        line[ed] = '\0';
    }
    bool succ() {
        while (true) {
            if (st == ed) {
                reread();
                if (st == ed) return false;
            }
            while (st != ed && isspace(line[st])) st++;
            if (st != ed) break;
        }
        if (ed - st <= 50) {
            bool sep = false;
            for (size_t i = st; i < ed; i++) {
                if (isspace(line[i])) {
                    sep = true;
                    break;
                }
            }
            if (!sep) reread();
        }
        return true;
    }
    template <class T, enable_if_t<is_same<T, string>::value, int> = 0>
    bool read_single(T& ref) {
        if (!succ()) return false;
        while (true) {
            size_t sz = 0;
            while (st + sz < ed && !isspace(line[st + sz])) sz++;
            ref.append(line + st, sz);
            st += sz;
            if (!sz || st != ed) break;
            reread();            
        }
        return true;
    }
    template <class T, enable_if_t<is_integral<T>::value, int> = 0>
    bool read_single(T& ref) {
        if (!succ()) return false;
        bool neg = false;
        if (line[st] == '-') {
            neg = true;
            st++;
        }
        ref = T(0);
        while (isdigit(line[st])) {
            ref = 10 * ref + (line[st++] & 0xf);
        }
        if (neg) ref = -ref;
        return true;
    }
    template <class T> bool read_single(V<T>& ref) {
        for (auto& d : ref) {
            if (!read_single(d)) return false;
        }
        return true;
    }
    void read() {}
    template <class H, class... T> void read(H& h, T&... t) {
        bool f = read_single(h);
        assert(f);
        read(t...);
    }
    Scanner(FILE* fp) : fd(fileno(fp)) {}
};

struct Printer {
  public:
    template <bool F = false> void write() {}
    template <bool F = false, class H, class... T>
    void write(const H& h, const T&... t) {
        if (F) write_single(' ');
        write_single(h);
        write<true>(t...);
    }
    template <class... T> void writeln(const T&... t) {
        write(t...);
        write_single('\n');
    }

    Printer(FILE* _fp) : fp(_fp) {}
    ~Printer() { flush(); }

  private:
    static constexpr size_t SIZE = 1 << 15;
    FILE* fp;
    char line[SIZE], small[50];
    size_t pos = 0;
    void flush() {
        fwrite(line, 1, pos, fp);
        pos = 0;
    }
    void write_single(const char& val) {
        if (pos == SIZE) flush();
        line[pos++] = val;
    }
    template <class T, enable_if_t<is_integral<T>::value, int> = 0>
    void write_single(T val) {
        if (pos > (1 << 15) - 50) flush();
        if (val == 0) {
            write_single('0');
            return;
        }
        if (val < 0) {
            write_single('-');
            val = -val;  // todo min
        }
        size_t len = 0;
        while (val) {
            small[len++] = char(0x30 | (val % 10));
            val /= 10;
        }
        for (size_t i = 0; i < len; i++) {
            line[pos + i] = small[len - 1 - i];
        }
        pos += len;
    }
    void write_single(const string& s) {
        for (char c : s) write_single(c);
    }
    void write_single(const char* s) {
        size_t len = strlen(s);
        for (size_t i = 0; i < len; i++) write_single(s[i]);
    }
    template <class T> void write_single(const V<T>& val) {
        auto n = val.size();
        for (size_t i = 0; i < n; i++) {
            if (i) write_single(' ');
            write_single(val[i]);
        }
    }
};
#line 2 "src/bitop.hpp"
// bit op
int popcnt(uint x) { return __builtin_popcount(x); }
int popcnt(ull x) { return __builtin_popcountll(x); }
int bsr(uint x) { return 31 - __builtin_clz(x); }
int bsr(ull x) { return 63 - __builtin_clzll(x); }
int bsf(uint x) { return __builtin_ctz(x); }
int bsf(ull x) { return __builtin_ctzll(x); }
#line 2 "src/math/modint.hpp"

template <uint MD> struct ModInt {
    using M = ModInt;
    static constexpr uint get_mod() { return MD; }
    const static M G;
    uint v;
    ModInt(ll _v = 0) { set_v(uint(_v % MD + MD)); }
    M& set_v(uint _v) {
        v = (_v < MD) ? _v : _v - MD;
        return *this;
    }
    explicit operator bool() const { return v != 0; }
    M operator-() const { return M() - *this; }
    M operator+(const M& r) const { return M().set_v(v + r.v); }
    M operator-(const M& r) const { return M().set_v(v + MD - r.v); }
    M operator*(const M& r) const { return M().set_v(uint(ull(v) * r.v % MD)); }
    M operator/(const M& r) const { return *this * r.inv(); }
    M& operator+=(const M& r) { return *this = *this + r; }
    M& operator-=(const M& r) { return *this = *this - r; }
    M& operator*=(const M& r) { return *this = *this * r; }
    M& operator/=(const M& r) { return *this = *this / r; }
    bool operator==(const M& r) const { return v == r.v; }
    M pow(ll n) const {
        M x = *this, r = 1;
        while (n) {
            if (n & 1) r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    M inv() const { return pow(MD - 2); }
    friend ostream& operator<<(ostream& os, const M& r) { return os << r.v; }
};
// using Mint = ModInt<998244353>;
// template<> const Mint Mint::G = Mint(3);
#line 2 "src/math/nft.hpp"

#line 4 "src/math/nft.hpp"

template <class Mint> void nft(bool type, V<Mint>& a) {
    int n = int(a.size()), s = 0;
    while ((1 << s) < n) s++;
    assert(1 << s == n);

    static V<Mint> ep, iep;
    while (int(ep.size()) <= s) {
        ep.push_back(Mint::G.pow(Mint(-1).v / (1 << ep.size())));
        iep.push_back(ep.back().inv());
    }
    V<Mint> b(n);
    for (int i = 1; i <= s; i++) {
        int w = 1 << (s - i);
        Mint base = type ? iep[i] : ep[i], now = 1;
        for (int y = 0; y < n / 2; y += w) {
            for (int x = 0; x < w; x++) {
                auto l = a[y << 1 | x];
                auto r = now * a[y << 1 | x | w];
                b[y | x] = l + r;
                b[y | x | n >> 1] = l - r;
            }
            now *= base;
        }
        swap(a, b);
    }
}

template <class Mint> V<Mint> multiply_nft(const V<Mint>& a, const V<Mint>& b) {
    int n = int(a.size()), m = int(b.size());
    if (!n || !m) return {};
    if (min(n, m) <= 8) {
        V<Mint> ans(n + m - 1);
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++) ans[i + j] += a[i] * b[j];
        return ans;
    }
    int lg = 0;
    while ((1 << lg) < n + m - 1) lg++;
    int z = 1 << lg;
    auto a2 = a, b2 = b;
    a2.resize(z);
    b2.resize(z);
    nft(false, a2);
    nft(false, b2);
    for (int i = 0; i < z; i++) a2[i] *= b2[i];
    nft(true, a2);
    a2.resize(n + m - 1);
    Mint iz = Mint(z).inv();
    for (int i = 0; i < n + m - 1; i++) a2[i] *= iz;
    return a2;
}

// Cooley-Tukey: input -> butterfly -> bit reversing -> output から
// bit reversingを抜いたもの 直接使うな
template <class Mint> void butterfly(bool type, V<Mint>& a) {
    int n = int(a.size()), h = 0;
    while ((1 << h) < n) h++;
    assert(1 << h == n);
    if (n == 1) return;

    static V<Mint> snow, sinow;
    if (snow.empty()) {
        Mint sep = Mint(1), siep = Mint(1);
        uint mod = Mint(-1).v;
        uint di = 4;
        while (mod % di == 0) {
            Mint ep = Mint::G.pow(mod / di);
            Mint iep = ep.inv();
            snow.push_back(siep * ep);
            sinow.push_back(sep * iep);
            sep *= ep;
            siep *= iep;
            di *= 2;
        }
    }

    if (!type) {
        // fft
        for (int ph = 1; ph <= h; ph++) {
            // phase ph: size w -> 2w の FFT, p 並列
            int w = 1 << (ph - 1), p = 1 << (h - ph);
            Mint now = Mint(1);
            for (int s = 0; s < w; s++) {
                int offset = s << (h - ph + 1);
                for (int i = 0; i < p; i++) {
                    auto l = a[i + offset];
                    auto r = a[i + offset + p] * now;
                    a[i + offset] = l + r;
                    a[i + offset + p] = l - r;
                }
                int u = bsf(~uint(s));
                now *= snow[u];
            }
        }
    } else {
        // ifft
        for (int ph = h; ph >= 1; ph--) {
            int w = 1 << (ph - 1), p = 1 << (h - ph);
            Mint inow = Mint(1);
            for (int s = 0; s < w; s++) {
                int offset = s << (h - ph + 1);
                for (int i = 0; i < p; i++) {
                    auto l = a[i + offset];
                    auto r = a[i + offset + p];
                    a[i + offset] = l + r;
                    a[i + offset + p] = (l - r) * inow;
                }
                int u = bsf(~uint(s));
                inow *= sinow[u];
            }
        }
    }
}

template <class Mint> V<Mint> multiply(const V<Mint>& a, const V<Mint>& b) {
    int n = int(a.size()), m = int(b.size());
    if (!n || !m) return {};
    if (min(n, m) < 8) {
        V<Mint> ans(n + m - 1);
        for (int i = 0; i < n; i++)
            for (int j = 0; j < m; j++) ans[i + j] += a[i] * b[j];
        return ans;
    }
    int lg = 0;
    while ((1 << lg) < n + m - 1) lg++;
    int z = 1 << lg;
    auto a2 = a;
    a2.resize(z);
    butterfly(false, a2);
    if (a == b) {
        for (int i = 0; i < z; i++) a2[i] *= a2[i];
    } else {
        auto b2 = b;
        b2.resize(z);
        butterfly(false, b2);
        for (int i = 0; i < z; i++) a2[i] *= b2[i];
    }
    butterfly(true, a2);
    a2.resize(n + m - 1);
    Mint iz = Mint(z).inv();
    for (int i = 0; i < n + m - 1; i++) a2[i] *= iz;
    return a2;
}
#line 8 "src/nft_convolution.test.cpp"

using Mint = ModInt<998244353>;
template <> const Mint Mint::G = Mint(3);

int main() {
    Scanner sc(stdin);
    Printer pr(stdout);

    int n, m;
    sc.read(n, m);

    V<Mint> a(n);
    for (int i = 0; i < n; i++) {
        sc.read(a[i].v);
    }
    V<Mint> b(m);
    for (int i = 0; i < m; i++) {
        sc.read(b[i].v);
    }
    auto c = multiply(a, b);
    for (auto x : c) {
        pr.write(x.v);
        pr.write(' ');
    }
    pr.writeln();
    return 0;
}
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