代码

// 给个STAR吧
// 再不济CV代码把这些链接留下吧，球球了
// https://github.com/With-Sky/HintFFT
// https://github.com/With-Sky/FFT-Benchmark
// https://github.com/With-Sky/HyperInt-mini
// https://space.bilibili.com/511540153
#include <tuple>
#include <iostream>
#include <complex>
#include <cstring>
#include <immintrin.h>
#ifndef HINT_SIMD_HPP
#define HINT_SIMD_HPP

#pragma GCC target("fma")

// Use AVX
// 256bit simd
using HintFloat = double;
using Complex = std::complex<HintFloat>;

// 2个复数并行
struct Complex2
{
    __m256d data;
    Complex2()
    {
        data = _mm256_setzero_pd();
    }
    Complex2(double input)
    {
        data = _mm256_set1_pd(input);
    }
    Complex2(__m256d input)
    {
        data = input;
    }
    Complex2(const Complex2 &input)
    {
        data = input.data;
    }
    // 从连续的数组构造
    Complex2(double const *ptr)
    {
        data = _mm256_loadu_pd(ptr);
    }
    Complex2(Complex a)
    {
        data = _mm256_broadcast_pd((__m128d *)&a);
    }
    Complex2(Complex a, Complex b)
    {
        data = _mm256_set_m128d(*(__m128d *)&b, *(__m128d *)&a);
    }
    Complex2(const Complex *ptr)
    {
        data = _mm256_loadu_pd((const double *)ptr);
    }
    void clr()
    {
        data = _mm256_setzero_pd();
    }
    void store(Complex *a) const
    {
        _mm256_storeu_pd((double *)a, data);
    }
    void print() const
    {
        double ary[4];
        _mm256_storeu_pd(ary, data);
        printf("(%lf,%lf) (%lf,%lf)\n", ary[0], ary[1], ary[2], ary[3]);
    }
    template <int M>
    Complex2 element_mask_neg() const
    {
        static const __m256d neg_mask = _mm256_castsi256_pd(
            _mm256_set_epi64x((M & 8ull) << 60, (M & 4ull) << 61, (M & 2ull) << 62, (M & 1ull) << 63));
        return _mm256_xor_pd(data, neg_mask);
    }
    template <int M>
    Complex2 element_permute() const
    {
        return _mm256_permute_pd(data, M);
    }
    template <int M>
    Complex2 element_permute64() const
    {
        return _mm256_permute4x64_pd(data, M);
    }
    Complex2 all_real() const
    {
        return _mm256_unpacklo_pd(data, data);
        // return _mm256_shuffle_pd(data, data, 0);
        // return _mm256_movedup_pd(data);
    }
    Complex2 all_imag() const
    {
        return _mm256_unpackhi_pd(data, data);
        // return _mm256_shuffle_pd(data, data, 15);
        // return element_permute<0XF>();
    }
    Complex2 swap() const
    {
        return _mm256_shuffle_pd(data, data, 5);
        // return element_permute<0X5>();
    }
    Complex2 mul_neg_i() const
    {
        static const __m256d subber{};
        return Complex2(_mm256_addsub_pd(subber, data)).swap();
        // return swap().conj();
    }
    Complex2 conj() const
    {
        return element_mask_neg<10>();
    }
    Complex2 linear_mul(Complex2 input) const
    {
        return _mm256_mul_pd(data, input.data);
    }
    Complex2 operator+(Complex2 input) const
    {
        return _mm256_add_pd(data, input.data);
    }
    Complex2 operator-(Complex2 input) const
    {
        return _mm256_sub_pd(data, input.data);
    }
    Complex2 operator*(Complex2 input) const
    {
        const __m256d a_rr = all_real().data;
        const __m256d a_ii = all_imag().data;
        const __m256d b_ir = input.swap().data;
        return _mm256_addsub_pd(_mm256_mul_pd(a_rr, input.data), _mm256_mul_pd(a_ii, b_ir));
        // auto imag = _mm256_mul_pd(all_imag().data, input.swap().data);
        // return _mm256_fmaddsub_pd(all_real().data, input.data, imag);
    }
    Complex2 operator/(Complex2 input) const
    {
        return _mm256_div_pd(data, input.data);
    }
};
#endif

#include <vector>
#include <complex>
#include <iostream>
#include <future>
#include <ctime>
#include <cstring>
// #include "stopwatch.hpp"

#define TABLE_ENABLE 0
#define MULTITHREAD 0   // 多线程 0 means no, 1 means yes
#define TABLE_PRELOAD 0 // 是否提前初始化表 0 means no, 1 means yes

namespace hint
{
    using UINT_8 = uint8_t;
    using UINT_16 = uint16_t;
    using UINT_32 = uint32_t;
    using UINT_64 = uint64_t;
    using INT_32 = int32_t;
    using INT_64 = int64_t;
    using ULONG = unsigned long;
    using LONG = long;
    // using HintFloat = double;
    // using Complex = std::complex<HintFloat>;

    constexpr UINT_64 HINT_CHAR_BIT = 8;
    constexpr UINT_64 HINT_SHORT_BIT = 16;
    constexpr UINT_64 HINT_INT_BIT = 32;
    constexpr UINT_64 HINT_INT8_0XFF = UINT8_MAX;
    constexpr UINT_64 HINT_INT8_0X10 = (UINT8_MAX + 1ull);
    constexpr UINT_64 HINT_INT16_0XFF = UINT16_MAX;
    constexpr UINT_64 HINT_INT16_0X10 = (UINT16_MAX + 1ull);
    constexpr UINT_64 HINT_INT32_0XFF = UINT32_MAX;
    constexpr UINT_64 HINT_INT32_0X01 = 1;
    constexpr UINT_64 HINT_INT32_0X80 = 0X80000000ull;
    constexpr UINT_64 HINT_INT32_0X7F = INT32_MAX;
    constexpr UINT_64 HINT_INT32_0X10 = (UINT32_MAX + 1ull);
    constexpr UINT_64 HINT_INT64_0X80 = INT64_MIN;
    constexpr UINT_64 HINT_INT64_0X7F = INT64_MAX;
    constexpr UINT_64 HINT_INT64_0XFF = UINT64_MAX;

    constexpr HintFloat HINT_PI = 3.1415926535897932384626433832795;
    constexpr HintFloat HINT_2PI = HINT_PI * 2;
    constexpr HintFloat HINT_HSQ_ROOT2 = 0.70710678118654752440084436210485;

    constexpr UINT_64 NTT_MOD1 = 3221225473;
    constexpr UINT_64 NTT_ROOT1 = 5;
    constexpr UINT_64 NTT_MOD2 = 3489660929;
    constexpr UINT_64 NTT_ROOT2 = 3;
    constexpr size_t NTT_MAX_LEN = 1ull << 28;

    /// @brief 生成不大于n的最大的2的幂次的数
    /// @param n
    /// @return 不大于n的最大的2的幂次的数
    template <typename T>
    constexpr T max_2pow(T n)
    {
        T res = 1;
        res <<= (sizeof(T) * 8 - 1);
        while (res > n)
        {
            res /= 2;
        }
        return res;
    }
    /// @brief 生成不小于n的最小的2的幂次的数
    /// @param n
    /// @return 不小于n的最小的2的幂次的数
    template <typename T>
    constexpr T min_2pow(T n)
    {
        T res = 1;
        while (res < n)
        {
            res *= 2;
        }
        return res;
    }
    template <typename T>
    constexpr size_t hint_log2(T n)
    {
        T res = 0;
        while (n > 1)
        {
            n /= 2;
            res++;
        }
        return res;
    }
    // 模板快速幂
    template <typename T>
    constexpr T qpow(T m, UINT_64 n)
    {
        T result = 1;
        while (n > 0)
        {
            if ((n & 1) != 0)
            {
                result = result * m;
            }
            m = m * m;
            n >>= 1;
        }
        return result;
    }
    template <typename T>
    constexpr std::pair<T, T> div_mod(T a, T b)
    {
        return std::make_pair(a / b, a % b);
    }
#if MULTITHREAD == 1
    const UINT_32 hint_threads = std::thread::hardware_concurrency();
    const UINT_32 log2_threads = std::ceil(hint_log2(hint_threads));
    std::atomic<UINT_32> cur_ths;
#endif

    // 模板数组拷贝
    template <typename T>
    void ary_copy(T *target, const T *source, size_t len)
    {
        if (len == 0 || target == source)
        {
            return;
        }
        if (len >= INT64_MAX)
        {
            throw("Ary too long\n");
        }
        std::memcpy(target, source, len * sizeof(T));
    }
    // 从其他类型数组拷贝到复数组
    template <typename T>
    inline void com_ary_combine_copy(Complex *target, const T &source1, size_t len1, const T &source2, size_t len2)
    {
        size_t min_len = std::min(len1, len2);
        size_t i = 0;
        while (i < min_len)
        {
            target[i] = Complex(source1[i], source2[i]);
            i++;
        }
        while (i < len1)
        {
            target[i].real(source1[i]);
            i++;
        }
        while (i < len2)
        {
            target[i].imag(source2[i]);
            i++;
        }
    }
    // FFT与类FFT变换的命名空间
    namespace hint_transform
    {
        // 返回单位圆上辐角为theta的点
        static Complex unit_root(HintFloat theta)
        {
            return std::polar<HintFloat>(1.0, theta);
        }
        // 返回单位圆上平分m份的第n个
        static Complex unit_root(size_t m, size_t n)
        {
            return unit_root((HINT_2PI * n) / m);
        }
        class ComplexTableY
        {
        private:
            std::vector<std::vector<Complex>> table1;
            std::vector<std::vector<Complex>> table3;
            INT_32 max_log_size = 2;
            INT_32 cur_log_size = 2;

            static constexpr size_t FAC = 1;

            ComplexTableY(const ComplexTableY &) = delete;
            ComplexTableY &operator=(const ComplexTableY &) = delete;

        public:
            ~ComplexTableY() {}
            // 初始化可以生成平分圆1<<shift份产生的单位根的表
            ComplexTableY(UINT_32 max_shift)
            {
                max_shift = std::max<size_t>(max_shift, 1);
                max_log_size = max_shift;
                table1.resize(max_shift + 1);
                table3.resize(max_shift + 1);
                table1[0] = table1[1] = table3[0] = table3[1] = std::vector<Complex>{1};
                table1[2] = table3[2] = std::vector<Complex>{1};
#if TABLE_PRELOAD == 1
                expand(max_shift);
#endif
            }
            void expand(INT_32 shift)
            {
                shift = std::max<INT_32>(shift, 2);
                if (shift > max_log_size)
                {
                    throw("FFT length too long for lut\n");
                }
                for (INT_32 i = cur_log_size + 1; i <= shift; i++)
                {
                    size_t len = 1ull << i, vec_size = len * FAC / 4;
                    table1[i].resize(vec_size);
                    table3[i].resize(vec_size);
                    table1[i][0] = table3[i][0] = Complex(1, 0);
                    for (size_t pos = 0; pos < vec_size / 2; pos++)
                    {
                        table1[i][pos * 2] = table1[i - 1][pos];
                        if (pos % 2 == 1)
                        {
                            Complex tmp = unit_root(-HINT_2PI * pos / len);
                            table1[i][pos] = tmp;
                            table1[i][vec_size - pos] = -Complex(tmp.imag(), tmp.real());
                        }
                    }
                    table1[i][vec_size / 2] = std::conj(unit_root(8, 1));
                    for (size_t pos = 0; pos < vec_size / 2; pos++)
                    {
                        table3[i][pos * 2] = table3[i - 1][pos];
                        if (pos % 2 == 1)
                        {
                            Complex tmp = get_omega(i, pos * 3);
                            table3[i][pos] = tmp;
                            table3[i][vec_size - pos] = Complex(tmp.imag(), tmp.real());
                        }
                    }
                    table3[i][vec_size / 2] = std::conj(unit_root(8, 3));
                }
                cur_log_size = std::max(cur_log_size, shift);
            }
            // 返回单位圆上辐角为theta的点

            static Complex unit_root(double theta)
            {
                return std::polar<double>(1.0, theta);
            }
            // 返回单位圆上平分m份的第n个
            static Complex unit_root(size_t m, size_t n)
            {
                return unit_root((HINT_2PI * n) / m);
            }
            // shift表示圆平分为1<<shift份,3n表示第几个单位根
            Complex get_omega(UINT_32 shift, size_t n) const
            {
                size_t vec_size = (size_t(1) << shift) / 4;
                if (n < vec_size)
                {
                    return table1[shift][n];
                }
                else if (n > vec_size)
                {
                    Complex tmp = table1[shift][vec_size * 2 - n];
                    return Complex(-tmp.real(), tmp.imag());
                }
                else
                {
                    return Complex(0, -1);
                }
            }
            // shift表示圆平分为1<<shift份,3n表示第几个单位根
            Complex get_omega3(UINT_32 shift, size_t n) const
            {
                return table3[shift][n];
            }
            // shift表示圆平分为1<<shift份,n表示第几个单位根
            Complex2 get_omegaX2(UINT_32 shift, size_t n) const
            {
                return Complex2(table1[shift].data() + n);
            }
            // shift表示圆平分为1<<shift份,3n表示第几个单位根
            Complex2 get_omega3X2(UINT_32 shift, size_t n) const
            {
                return Complex2(table3[shift].data() + n);
            }
            // shift表示圆平分为1<<shift份,n表示第几个单位根
            const Complex *get_omega_ptr(UINT_32 shift, size_t n) const
            {
                return table1[shift].data() + n;
            }
            // shift表示圆平分为1<<shift份,3n表示第几个单位根
            const Complex *get_omega3_ptr(UINT_32 shift, size_t n) const
            {
                return table3[shift].data() + n;
            }
        };

        constexpr size_t lut_max_rank = 21;
        static ComplexTableY TABLE(lut_max_rank);

        // 二进制逆序
        template <typename T>
        void binary_reverse_swap(T &ary, size_t len)
        {
            size_t i = 0;
            for (size_t j = 1; j < len - 1; j++)
            {
                size_t k = len >> 1;
                i ^= k;
                while (k > i)
                {
                    k >>= 1;
                    i ^= k;
                };
                if (j < i)
                {
                    std::swap(ary[i], ary[j]);
                }
            }
        }
        // 2点fft
        template <typename T>
        inline void fft_2point(T &sum, T &diff)
        {
            T tmp0 = sum;
            T tmp1 = diff;
            sum = tmp0 + tmp1;
            diff = tmp0 - tmp1;
        }
        // 4点fft
        inline void fft_4point(Complex *input, size_t rank = 1)
        {
            Complex tmp0 = input[0];
            Complex tmp1 = input[rank];
            Complex tmp2 = input[rank * 2];
            Complex tmp3 = input[rank * 3];

            fft_2point(tmp0, tmp2);
            fft_2point(tmp1, tmp3);
            tmp3 = Complex(tmp3.imag(), -tmp3.real());

            input[0] = tmp0 + tmp1;
            input[rank] = tmp2 + tmp3;
            input[rank * 2] = tmp0 - tmp1;
            input[rank * 3] = tmp2 - tmp3;
        }
        inline void fft_dit_4point_avx(Complex *input)
        {
            static const __m256d neg_mask = _mm256_castsi256_pd(
                _mm256_set_epi64x(INT64_MIN, 0, 0, 0));
            __m256d tmp0 = _mm256_loadu_pd(reinterpret_cast<double *>(input));     // c0,c1
            __m256d tmp1 = _mm256_loadu_pd(reinterpret_cast<double *>(input + 2)); // c2,c3

            __m256d tmp2 = _mm256_permute2f128_pd(tmp0, tmp1, 0x20); // c0,c2
            __m256d tmp3 = _mm256_permute2f128_pd(tmp0, tmp1, 0x31); // c1,c3

            tmp0 = _mm256_add_pd(tmp2, tmp3); // c0+c1,c2+c3
            tmp1 = _mm256_sub_pd(tmp2, tmp3); // c0-c1,c2-c3

            tmp2 = _mm256_permute2f128_pd(tmp0, tmp1, 0x20); // c0+c1,c0-c1;(A,B)
            tmp3 = _mm256_permute2f128_pd(tmp0, tmp1, 0x31); // c2+c3,c2-c3

            tmp3 = _mm256_permute_pd(tmp3, 0b0110);
            tmp3 = _mm256_xor_pd(tmp3, neg_mask); // (C,D)

            tmp0 = _mm256_add_pd(tmp2, tmp3); // A+C,B+D
            tmp1 = _mm256_sub_pd(tmp2, tmp3); // A-C,B-D

            _mm256_storeu_pd(reinterpret_cast<double *>(input), tmp0);
            _mm256_storeu_pd(reinterpret_cast<double *>(input + 2), tmp1);
        }
        inline void fft_dit_8point_avx(Complex *input)
        {
            static const __m256d neg_mask = _mm256_castsi256_pd(_mm256_set_epi64x(INT64_MIN, 0, 0, 0));
            static const __m256d mul1 = _mm256_set_pd(0.70710678118654752440084436210485, 0.70710678118654752440084436210485, 0, 0);
            static const __m256d mul2 = _mm256_set_pd(-0.70710678118654752440084436210485, -0.70710678118654752440084436210485, -1, 1);
            __m256d tmp0 = _mm256_loadu_pd(reinterpret_cast<double *>(input));     // c0,c1
            __m256d tmp1 = _mm256_loadu_pd(reinterpret_cast<double *>(input + 2)); // c2,c3
            __m256d tmp2 = _mm256_loadu_pd(reinterpret_cast<double *>(input + 4)); // c0,c1
            __m256d tmp3 = _mm256_loadu_pd(reinterpret_cast<double *>(input + 6)); // c2,c3

            __m256d tmp4 = _mm256_permute2f128_pd(tmp0, tmp1, 0x20); // c0,c2
            __m256d tmp5 = _mm256_permute2f128_pd(tmp0, tmp1, 0x31); // c1,c3
            __m256d tmp6 = _mm256_permute2f128_pd(tmp2, tmp3, 0x20); // c0,c2
            __m256d tmp7 = _mm256_permute2f128_pd(tmp2, tmp3, 0x31); // c1,c3

            tmp0 = _mm256_add_pd(tmp4, tmp5); // c0+c1,c2+c3
            tmp1 = _mm256_sub_pd(tmp4, tmp5); // c0-c1,c2-c3
            tmp2 = _mm256_add_pd(tmp6, tmp7); // c0+c1,c2+c3
            tmp3 = _mm256_sub_pd(tmp6, tmp7); // c0-c1,c2-c3

            tmp4 = _mm256_permute2f128_pd(tmp0, tmp1, 0x20); // c0+c1,c0-c1;(A,B)
            tmp5 = _mm256_permute2f128_pd(tmp0, tmp1, 0x31); // c2+c3,c2-c3
            tmp6 = _mm256_permute2f128_pd(tmp2, tmp3, 0x20); // c0+c1,c0-c1;(A,B)
            tmp7 = _mm256_permute2f128_pd(tmp2, tmp3, 0x31); // c2+c3,c2-c3

            tmp5 = _mm256_permute_pd(tmp5, 0b0110);
            tmp5 = _mm256_xor_pd(tmp5, neg_mask); // (C,D)
            tmp7 = _mm256_permute_pd(tmp7, 0b0110);
            tmp7 = _mm256_xor_pd(tmp7, neg_mask); // (C,D)

            tmp0 = _mm256_add_pd(tmp4, tmp5); // A+C,B+D
            tmp1 = _mm256_sub_pd(tmp4, tmp5); // A-C,B-D
            tmp2 = _mm256_add_pd(tmp6, tmp7); // A+C,B+D
            tmp3 = _mm256_sub_pd(tmp6, tmp7); // A-C,B-D

            // 2X4point-done
            tmp6 = _mm256_permute_pd(tmp2, 0b0110);
            tmp6 = _mm256_addsub_pd(tmp6, tmp2);
            tmp6 = _mm256_permute_pd(tmp6, 0b0110);
            tmp6 = _mm256_mul_pd(tmp6, mul1);
            tmp2 = _mm256_blend_pd(tmp2, tmp6, 0b1100);

            tmp7 = _mm256_permute_pd(tmp3, 0b0101);
            tmp3 = _mm256_addsub_pd(tmp3, tmp7);
            tmp3 = _mm256_blend_pd(tmp7, tmp3, 0b1100);
            tmp3 = _mm256_mul_pd(tmp3, mul2);

            tmp4 = _mm256_add_pd(tmp0, tmp2);
            tmp5 = _mm256_add_pd(tmp1, tmp3);
            tmp6 = _mm256_sub_pd(tmp0, tmp2);
            tmp7 = _mm256_sub_pd(tmp1, tmp3);
            _mm256_storeu_pd(reinterpret_cast<double *>(input), tmp4);
            _mm256_storeu_pd(reinterpret_cast<double *>(input + 2), tmp5);
            _mm256_storeu_pd(reinterpret_cast<double *>(input + 4), tmp6);
            _mm256_storeu_pd(reinterpret_cast<double *>(input + 6), tmp7);
        }
        inline void fft_dif_4point_avx(Complex *input)
        {
            __m256d tmp0 = _mm256_loadu_pd(reinterpret_cast<double *>(input));     // c0,c1
            __m256d tmp1 = _mm256_loadu_pd(reinterpret_cast<double *>(input + 2)); // c2,c3

            __m256d tmp2 = _mm256_add_pd(tmp0, tmp1); // c0+c2,c1+c3;
            __m256d tmp3 = _mm256_sub_pd(tmp0, tmp1); // c0-c2,c1-c3;
            tmp3 = _mm256_permute_pd(tmp3, 0b0110);   // c0-c2,r(c1-c3);

            static const __m256d neg_mask = _mm256_castsi256_pd(
                _mm256_set_epi64x(INT64_MIN, 0, 0, 0));
            tmp3 = _mm256_xor_pd(tmp3, neg_mask);

            tmp0 = _mm256_permute2f128_pd(tmp2, tmp3, 0x20); // A,C
            tmp1 = _mm256_permute2f128_pd(tmp2, tmp3, 0x31); // B,D

            tmp2 = _mm256_add_pd(tmp0, tmp1); // A+B,C+D
            tmp3 = _mm256_sub_pd(tmp0, tmp1); // A-B,C-D

            tmp0 = _mm256_permute2f128_pd(tmp2, tmp3, 0x20);
            tmp1 = _mm256_permute2f128_pd(tmp2, tmp3, 0x31);

            _mm256_storeu_pd(reinterpret_cast<double *>(input), tmp0);
            _mm256_storeu_pd(reinterpret_cast<double *>(input + 2), tmp1);
        }
        inline void fft_dif_8point_avx(Complex *input)
        {
            static const __m256d neg_mask = _mm256_castsi256_pd(_mm256_set_epi64x(INT64_MIN, 0, 0, 0));
            static const __m256d mul1 = _mm256_set_pd(0.70710678118654752440084436210485, 0.70710678118654752440084436210485, 0, 0);
            static const __m256d mul2 = _mm256_set_pd(-0.70710678118654752440084436210485, -0.70710678118654752440084436210485, -1, 1);
            __m256d tmp0 = _mm256_loadu_pd(reinterpret_cast<double *>(input));     // c0,c1
            __m256d tmp1 = _mm256_loadu_pd(reinterpret_cast<double *>(input + 2)); // c2,c3
            __m256d tmp2 = _mm256_loadu_pd(reinterpret_cast<double *>(input + 4)); // c4,c5
            __m256d tmp3 = _mm256_loadu_pd(reinterpret_cast<double *>(input + 6)); // c6,c7

            __m256d tmp4 = _mm256_add_pd(tmp0, tmp2);
            __m256d tmp5 = _mm256_add_pd(tmp1, tmp3);
            __m256d tmp6 = _mm256_sub_pd(tmp0, tmp2);
            __m256d tmp7 = _mm256_sub_pd(tmp1, tmp3);

            tmp2 = _mm256_permute_pd(tmp6, 0b0110);
            tmp2 = _mm256_addsub_pd(tmp2, tmp6);
            tmp2 = _mm256_permute_pd(tmp2, 0b0110);
            tmp2 = _mm256_mul_pd(tmp2, mul1);
            tmp6 = _mm256_blend_pd(tmp6, tmp2, 0b1100);

            tmp3 = _mm256_permute_pd(tmp7, 0b0101);
            tmp7 = _mm256_addsub_pd(tmp7, tmp3);
            tmp7 = _mm256_blend_pd(tmp3, tmp7, 0b1100);
            tmp7 = _mm256_mul_pd(tmp7, mul2);

            // 2X4point
            tmp0 = _mm256_add_pd(tmp4, tmp5);
            tmp1 = _mm256_sub_pd(tmp4, tmp5);
            tmp1 = _mm256_permute_pd(tmp1, 0b0110);
            tmp1 = _mm256_xor_pd(tmp1, neg_mask);

            tmp2 = _mm256_add_pd(tmp6, tmp7);
            tmp3 = _mm256_sub_pd(tmp6, tmp7);
            tmp3 = _mm256_permute_pd(tmp3, 0b0110);
            tmp3 = _mm256_xor_pd(tmp3, neg_mask);

            tmp4 = _mm256_permute2f128_pd(tmp0, tmp1, 0x20);
            tmp5 = _mm256_permute2f128_pd(tmp0, tmp1, 0x31);
            tmp6 = _mm256_permute2f128_pd(tmp2, tmp3, 0x20);
            tmp7 = _mm256_permute2f128_pd(tmp2, tmp3, 0x31);

            tmp0 = _mm256_add_pd(tmp4, tmp5);
            tmp1 = _mm256_sub_pd(tmp4, tmp5);
            tmp2 = _mm256_add_pd(tmp6, tmp7);
            tmp3 = _mm256_sub_pd(tmp6, tmp7);

            tmp4 = _mm256_permute2f128_pd(tmp0, tmp1, 0x20);
            tmp5 = _mm256_permute2f128_pd(tmp0, tmp1, 0x31);
            tmp6 = _mm256_permute2f128_pd(tmp2, tmp3, 0x20);
            tmp7 = _mm256_permute2f128_pd(tmp2, tmp3, 0x31);

            _mm256_storeu_pd(reinterpret_cast<double *>(input), tmp4);
            _mm256_storeu_pd(reinterpret_cast<double *>(input + 2), tmp5);
            _mm256_storeu_pd(reinterpret_cast<double *>(input + 4), tmp6);
            _mm256_storeu_pd(reinterpret_cast<double *>(input + 6), tmp7);
        }

        // fft分裂基时间抽取蝶形变换
        inline void fft_split_radix_dit_butterfly(Complex omega, Complex omega_cube,
                                                  Complex *input, size_t rank)
        {
            Complex tmp0 = input[0];
            Complex tmp1 = input[rank];
            Complex tmp2 = input[rank * 2] * omega;
            Complex tmp3 = input[rank * 3] * omega_cube;

            fft_2point(tmp2, tmp3);
            tmp3 = Complex(tmp3.imag(), -tmp3.real());

            input[0] = tmp0 + tmp2;
            input[rank] = tmp1 + tmp3;
            input[rank * 2] = tmp0 - tmp2;
            input[rank * 3] = tmp1 - tmp3;
        }
        // fft分裂基频率抽取蝶形变换
        inline void fft_split_radix_dif_butterfly(Complex omega, Complex omega_cube,
                                                  Complex *input, size_t rank)
        {
            Complex tmp0 = input[0];
            Complex tmp1 = input[rank];
            Complex tmp2 = input[rank * 2];
            Complex tmp3 = input[rank * 3];

            fft_2point(tmp0, tmp2);
            fft_2point(tmp1, tmp3);
            tmp3 = Complex(tmp3.imag(), -tmp3.real());

            input[0] = tmp0;
            input[rank] = tmp1;
            input[rank * 2] = (tmp2 + tmp3) * omega;
            input[rank * 3] = (tmp2 - tmp3) * omega_cube;
        }
        // fft分裂基时间抽取蝶形变换
        inline void fft_split_radix_dit_butterfly(const Complex2 &omega, const Complex2 &omega_cube,
                                                  Complex *input, size_t rank)
        {
            Complex2 tmp0 = input;
            Complex2 tmp1 = input + rank;
            Complex2 tmp2 = Complex2(input + rank * 2) * omega;
            Complex2 tmp3 = Complex2(input + rank * 3) * omega_cube;

            fft_2point(tmp2, tmp3);
            tmp3 = tmp3.mul_neg_i();

            (tmp0 + tmp2).store(input);
            (tmp1 + tmp3).store(input + rank);
            (tmp0 - tmp2).store(input + rank * 2);
            (tmp1 - tmp3).store(input + rank * 3);
        }
        // fft分裂基时间抽取蝶形变换
        inline void fft_split_radix_dit_butterfly(const Complex *omega, const Complex *omega_cube,
                                                  Complex *input, size_t rank)
        {
            Complex2 tmp0 = input;
            Complex2 tmp4 = input + 2;
            Complex2 tmp1 = input + rank;
            Complex2 tmp5 = input + rank + 2;
            Complex2 tmp2 = Complex2(input + rank * 2) * Complex2(omega);
            Complex2 tmp6 = Complex2(input + rank * 2 + 2) * Complex2(omega + 2);
            Complex2 tmp3 = Complex2(input + rank * 3) * Complex2(omega_cube);
            Complex2 tmp7 = Complex2(input + rank * 3 + 2) * Complex2(omega_cube + 2);

            fft_2point(tmp2, tmp3);
            fft_2point(tmp6, tmp7);
            tmp3 = tmp3.mul_neg_i();
            tmp7 = tmp7.mul_neg_i();

            (tmp0 + tmp2).store(input);
            (tmp4 + tmp6).store(input + 2);
            (tmp1 + tmp3).store(input + rank);
            (tmp5 + tmp7).store(input + rank + 2);
            (tmp0 - tmp2).store(input + rank * 2);
            (tmp4 - tmp6).store(input + rank * 2 + 2);
            (tmp1 - tmp3).store(input + rank * 3);
            (tmp5 - tmp7).store(input + rank * 3 + 2);
        }
        // fft分裂基频率抽取蝶形变换
        inline void fft_split_radix_dif_butterfly(const Complex *omega, const Complex *omega_cube,
                                                  Complex *input, size_t rank)
        {
            Complex2 tmp0 = input;
            Complex2 tmp4 = input + 2;
            Complex2 tmp1 = input + rank;
            Complex2 tmp5 = input + rank + 2;
            Complex2 tmp2 = input + rank * 2;
            Complex2 tmp6 = input + rank * 2 + 2;
            Complex2 tmp3 = input + rank * 3;
            Complex2 tmp7 = input + rank * 3 + 2;

            fft_2point(tmp0, tmp2);
            fft_2point(tmp1, tmp3);
            fft_2point(tmp4, tmp6);
            fft_2point(tmp5, tmp7);
            tmp3 = tmp3.mul_neg_i();
            tmp7 = tmp7.mul_neg_i();

            tmp0.store(input);
            tmp4.store(input + 2);
            tmp1.store(input + rank);
            tmp5.store(input + rank + 2);
            ((tmp2 + tmp3) * Complex2(omega)).store(input + rank * 2);
            ((tmp6 + tmp7) * Complex2(omega + 2)).store(input + rank * 2 + 2);
            ((tmp2 - tmp3) * Complex2(omega_cube)).store(input + rank * 3);
            ((tmp6 - tmp7) * Complex2(omega_cube + 2)).store(input + rank * 3 + 2);
        }
        // fft分裂基频率抽取蝶形变换
        inline void fft_split_radix_dif_butterfly(const Complex2 &omega, const Complex2 &omega_cube,
                                                  Complex *input, size_t rank)
        {
            Complex2 tmp0 = (input);
            Complex2 tmp1 = (input + rank);
            Complex2 tmp2 = (input + rank * 2);
            Complex2 tmp3 = (input + rank * 3);

            fft_2point(tmp0, tmp2);
            fft_2point(tmp1, tmp3);
            tmp3 = tmp3.mul_neg_i();

            tmp0.store(input);
            tmp1.store(input + rank);
            ((tmp2 + tmp3) * omega).store(input + rank * 2);
            ((tmp2 - tmp3) * omega_cube).store(input + rank * 3);
        }
        // 求共轭复数及归一化，逆变换用
        inline void fft_conj(Complex *input, size_t fft_len, HintFloat div = 1)
        {
            for (size_t i = 0; i < fft_len; i++)
            {
                input[i] = std::conj(input[i]) / div;
            }
        }
        // 归一化,逆变换用
        inline void fft_normalize(Complex *input, size_t fft_len)
        {
            HintFloat len = static_cast<HintFloat>(fft_len);
            for (size_t i = 0; i < fft_len; i++)
            {
                input[i] /= len;
            }
        }
        // 模板化时间抽取分裂基fft
        static constexpr HintFloat cos_1_8 = 0.70710678118654752440084436210485;
        static constexpr HintFloat cos_1_16 = 0.92387953251128675612818318939679;
        static constexpr HintFloat sin_1_16 = 0.3826834323650897717284599840304;
        static constexpr Complex w1(cos_1_16, -sin_1_16), w3(sin_1_16, -cos_1_16), w9(-cos_1_16, sin_1_16);
        static constexpr Complex omega1_table[4] = {Complex(1), w1, Complex(cos_1_8, -cos_1_8), w3};
        static constexpr Complex omega3_table[4] = {Complex(1), w3, Complex(-cos_1_8, -cos_1_8), w9};
        static const Complex2 omega0(omega1_table), omega1(omega1_table + 2);
        static const Complex2 omega_cu0(omega3_table), omega_cu1(omega3_table + 2);
        template <size_t LEN>
        void fft_split_radix_dit_template(Complex *input)
        {
            constexpr size_t log_len = hint_log2(LEN);
            constexpr size_t half_len = LEN / 2, quarter_len = LEN / 4;
            fft_split_radix_dit_template<half_len>(input);
            fft_split_radix_dit_template<quarter_len>(input + half_len);
            fft_split_radix_dit_template<quarter_len>(input + half_len + quarter_len);
#if TABLE_ENABLE == 1
            for (size_t i = 0; i < quarter_len; i += 4)
            {
                auto omega = TABLE.get_omega_ptr(log_len, i);
                auto omega_cube = TABLE.get_omega3_ptr(log_len, i);
                fft_split_radix_dit_butterfly(omega, omega_cube, input + i, quarter_len);
            }
#else
            static const Complex unit1 = std::conj(unit_root(LEN, 1));
            static const Complex unit3 = std::conj(unit_root(LEN, 3));
            static const Complex unit2 = std::conj(unit_root(LEN, 2));
            static const Complex unit6 = std::conj(unit_root(LEN, 6));
            static const Complex2 unit(unit2, unit2);
            static const Complex2 unit_cube(unit6, unit6);
            Complex2 omega(Complex(1, 0), unit1);
            Complex2 omega_cube(Complex(1, 0), unit3);
            for (size_t i = 0; i < quarter_len; i += 2)
            {
                fft_split_radix_dit_butterfly(omega, omega_cube, input + i, quarter_len);
                omega = omega * unit;
                omega_cube = omega_cube * unit_cube;
            }
#endif
        }
        template <>
        void fft_split_radix_dit_template<0>(Complex *input) {}
        template <>
        void fft_split_radix_dit_template<1>(Complex *input) {}
        template <>
        void fft_split_radix_dit_template<2>(Complex *input)
        {
            fft_2point(input[0], input[1]);
        }
        template <>
        void fft_split_radix_dit_template<4>(Complex *input)
        {
            fft_dit_4point_avx(input);
        }
        template <>
        void fft_split_radix_dit_template<8>(Complex *input)
        {
            fft_dit_8point_avx(input);
        }
        template <>
        void fft_split_radix_dit_template<16>(Complex *input)
        {
            constexpr size_t log_len = hint_log2(16);
            fft_dit_8point_avx(input);
            fft_dit_4point_avx(input + 8);
            fft_dit_4point_avx(input + 12);
            fft_split_radix_dit_butterfly(omega0, omega_cu0, input, 4);
            fft_split_radix_dit_butterfly(omega1, omega_cu1, input + 2, 4);
        }
        // 模板化频率抽取分裂基fft
        template <size_t LEN>
        void fft_split_radix_dif_template(Complex *input)
        {
            constexpr size_t log_len = hint_log2(LEN);
            constexpr size_t half_len = LEN / 2, quarter_len = LEN / 4;
#if TABLE_ENABLE == 1
            for (size_t i = 0; i < quarter_len; i += 4)
            {
                auto omega = TABLE.get_omega_ptr(log_len, i);
                auto omega_cube = TABLE.get_omega3_ptr(log_len, i);
                fft_split_radix_dif_butterfly(omega, omega_cube, input + i, quarter_len);
            }
#else
            static const Complex unit1 = std::conj(unit_root(LEN, 1));
            static const Complex unit3 = std::conj(unit_root(LEN, 3));
            static const Complex unit2 = std::conj(unit_root(LEN, 2));
            static const Complex unit6 = std::conj(unit_root(LEN, 6));
            static const Complex2 unit(unit2, unit2);
            static const Complex2 unit_cube(unit6, unit6);
            Complex2 omega(Complex(1, 0), unit1);
            Complex2 omega_cube(Complex(1, 0), unit3);
            for (size_t i = 0; i < quarter_len; i += 2)
            {
                fft_split_radix_dif_butterfly(omega, omega_cube, input + i, quarter_len);
                omega = omega * unit;
                omega_cube = omega_cube * unit_cube;
            }
#endif
            fft_split_radix_dif_template<half_len>(input);
            fft_split_radix_dif_template<quarter_len>(input + half_len);
            fft_split_radix_dif_template<quarter_len>(input + half_len + quarter_len);
        }
        template <>
        void fft_split_radix_dif_template<0>(Complex *input) {}
        template <>
        void fft_split_radix_dif_template<1>(Complex *input) {}
        template <>
        void fft_split_radix_dif_template<2>(Complex *input)
        {
            fft_2point(input[0], input[1]);
        }
        template <>
        void fft_split_radix_dif_template<4>(Complex *input)
        {
            fft_dif_4point_avx(input);
        }
        template <>
        void fft_split_radix_dif_template<8>(Complex *input)
        {
            fft_dif_8point_avx(input);
        }
        template <>
        void fft_split_radix_dif_template<16>(Complex *input)
        {
            constexpr size_t log_len = hint_log2(16);
            fft_split_radix_dif_butterfly(omega0, omega_cu0, input, 4);
            fft_split_radix_dif_butterfly(omega1, omega_cu1, input + 2, 4);
            fft_dif_8point_avx(input);
            fft_dif_4point_avx(input + 8);
            fft_dif_4point_avx(input + 12);
        }

        // 辅助选择函数
        template <size_t LEN = 1>
        void fft_split_radix_dit_template_alt(Complex *input, size_t fft_len)
        {
            if (fft_len < LEN)
            {
                fft_split_radix_dit_template_alt<LEN / 2>(input, fft_len);
                return;
            }
            fft_split_radix_dit_template<LEN>(input);
        }
        template <>
        void fft_split_radix_dit_template_alt<0>(Complex *input, size_t fft_len) {}

        // 辅助选择函数
        template <size_t LEN = 1>
        void fft_split_radix_dif_template_alt(Complex *input, size_t fft_len)
        {
            if (fft_len < LEN)
            {
                fft_split_radix_dif_template_alt<LEN / 2>(input, fft_len);
                return;
            }
            fft_split_radix_dif_template<LEN>(input);
        }
        template <>
        void fft_split_radix_dif_template_alt<0>(Complex *input, size_t fft_len) {}

        auto fft_split_radix_dit = fft_split_radix_dit_template_alt<size_t(1) << lut_max_rank>;
        auto fft_split_radix_dif = fft_split_radix_dif_template_alt<size_t(1) << lut_max_rank>;

        /// @brief 时间抽取基2fft
        /// @param input 复数组
        /// @param fft_len 数组长度
        /// @param bit_rev 是否逆序
        inline void fft_dit(Complex *input, size_t fft_len, bool bit_rev = true)
        {
            fft_len = max_2pow(fft_len);
#if TABLE_ENABLE == 1
            TABLE.expand(hint_log2(fft_len));
#endif
            if (bit_rev)
            {
                binary_reverse_swap(input, fft_len);
            }
            fft_split_radix_dit(input, fft_len);
        }

        /// @brief 频率抽取基2fft
        /// @param input 复数组
        /// @param fft_len 数组长度
        /// @param bit_rev 是否逆序
        inline void fft_dif(Complex *input, size_t fft_len, bool bit_rev = true)
        {
            fft_len = max_2pow(fft_len);
#if TABLE_ENABLE == 1
            TABLE.expand(hint_log2(fft_len));
#endif
            fft_split_radix_dif(input, fft_len);
            if (bit_rev)
            {
                binary_reverse_swap(input, fft_len);
            }
        }

        inline std::string ui64to_string(UINT_64 input, UINT_8 digits)
        {
            std::string result(digits, '0');
            for (UINT_8 i = 0; i < digits; i++)
            {
                result[digits - i - 1] = static_cast<char>(input % 10 + '0');
                input /= 10;
            }
            return result;
        }
        constexpr UINT_64 stoui64(char *s, size_t dig = 4)
        {
            UINT_64 result = 0;
            for (size_t i = 0; i < dig; i++)
            {
                result *= 10;
                result += (s[i] - '0');
            }
            return result;
        }
        constexpr UINT_64 BASE = 10;
        template <size_t DIG>
        constexpr UINT_64 stoui64(char *s)
        {
            UINT_64 factor = qpow(BASE, DIG - 1);
            return (*s - '0') * factor + stoui64<DIG - 1>(s + 1);
        }
        template <>
        constexpr UINT_64 stoui64<0>(char *s)
        {
            return 0;
        }
        constexpr UINT_64 stobase10000(char *s)
        {
            return (s[0] - '0') * 1000 + (s[1] - '0') * 100 + (s[2] - '0') * 10 + s[3] - '0';
        }
        constexpr UINT_64 stobase100000(char *s)
        {
            return (s[0] - '0') * 10000 + (s[1] - '0') * 1000 + (s[2] - '0') * 100 + (s[3] - '0') * 10 + s[4] - '0';
        }
        static constexpr INT_64 DIGIT = 4;
        inline size_t char_to_real(char *buffer, Complex *comary, size_t str_len)
        {
            hint::INT_64 len = str_len, pos = len, i = 0;
            len = (len + DIGIT - 1) / DIGIT;
            while (pos - DIGIT > 0)
            {
                hint::UINT_64 tmp = stoui64<DIGIT>(buffer + pos - DIGIT);
                // hint::UINT_64 tmp = stobase10000(buffer + pos - DIGIT);
                comary[i].real(tmp);
                i++;
                pos -= DIGIT;
            }
            if (pos > 0)
            {
                hint::UINT_64 tmp = stoui64(buffer, pos);
                comary[i].real(tmp);
            }
            return len;
        }
        inline size_t char_to_imag(char *buffer, Complex *comary, size_t str_len)
        {
            hint::INT_64 len = str_len, pos = len, i = 0;
            len = (len + DIGIT - 1) / DIGIT;
            while (pos - DIGIT > 0)
            {
                hint::UINT_64 tmp = stoui64<DIGIT>(buffer + pos - DIGIT);
                // hint::UINT_64 tmp = stobase10000(buffer + pos - DIGIT);
                comary[i].imag(tmp);
                i++;
                pos -= DIGIT;
            }
            if (pos > 0)
            {
                hint::UINT_64 tmp = stoui64(buffer, pos);
                comary[i].imag(tmp);
            }
            return len;
        }
        inline void num_to_s(char *s, UINT_64 num)
        {
            char c = '0';
            int i = DIGIT;
            while (i > 0)
            {
                i--;
                std::tie(num, c) = div_mod<UINT_64>(num, 10);
                s[i] = c + '0';
            }
        }
        constexpr void num_to_s_base10000(char *s, UINT_64 num)
        {
            s[3] = '0' + num % 10;
            s[2] = '0' + num / 10 % 10;
            s[1] = '0' + num / 100 % 10;
            s[0] = '0' + num / 1000 % 10;
        }
        constexpr void num_to_s_base100000(char *s, UINT_64 num)
        {
            s[4] = '0' + num % 10;
            s[3] = '0' + num / 10 % 10;
            s[2] = '0' + num / 100 % 10;
            s[1] = '0' + num / 1000 % 10;
            s[0] = '0' + num / 10000 % 10;
        }
    }
}
using namespace std;
using namespace hint;
using namespace hint_transform;
void poly_multiply(unsigned *a, int n, unsigned *b, int m, unsigned *c)
{
    size_t len1 = n + 1, len2 = m + 1, out_len = len1 + len2 - 1;
    size_t fft_len = min_2pow(out_len);
    // static Complex2 avx_ary[1 << 20];
    // Complex2 *avx_ary = new Complex2[fft_len / 2];
    static Complex fft_ary[1 << 21];
    com_ary_combine_copy(fft_ary, a, len1, b, len2);
    fft_dif(fft_ary, fft_len, false); // 优化FFT
    HintFloat inv = -0.5 / fft_len;
    Complex2 invx4(inv);
    for (size_t i = 0; i < fft_len; i += 2)
    {
        // Complex tmp = fft_ary[i];
        // fft_ary[i] = std::conj(tmp * tmp) * inv;
        Complex2 tmp = fft_ary + i;
        tmp = tmp * tmp.linear_mul(invx4);
        (tmp.conj()).store(fft_ary + i);
    }
    fft_dit(fft_ary, fft_len, false); // 优化FFT
    for (size_t i = 0; i < out_len; i++)
    {
        c[i] = unsigned(fft_ary[i].imag() + 0.5);
    }
}

class QPrint
{
private:
    char *data = nullptr;
    size_t pos = 0;

public:
    QPrint(size_t max_len)
    {
        data = new char[max_len];
    }
    ~QPrint()
    {
        if (data != nullptr)
        {
            delete[] data;
        }
    }
    void operator<<(uint64_t n)
    {
        if (pos != 0)
        {
            data[pos] = ' ';
            pos++;
        }
        if (n == 0)
        {
            data[pos] = '0';
            pos++;
            return;
        }
        size_t digs = pos;
        uint64_t tmp = n;
        while (n > 0)
        {
            n /= 10;
            digs++;
        }
        pos = digs;
        while (tmp > 0)
        {
            digs--;
            data[digs] = tmp % 10 + '0';
            tmp /= 10;
        }
        data[pos] = '\0';
    }
    void operator<<(const std::string &s)
    {
        if (pos != 0)
        {
            data[pos] = ' ';
            pos++;
        }
        memcpy(data + pos, s.data(), s.size());
        pos += s.size();
        data[pos] = '\0';
    }
    void put() const
    {
        puts(data);
    }
};
inline int ReadNum()
{
    int res = 0;
    int tmp = getchar();
    while (tmp < '0' || '9' < tmp)
    {
        tmp = getchar();
    }
    while ('0' <= tmp && tmp <= '9')
    {
        res *= 10;
        res += (tmp - '0');
        tmp = getchar();
    }
    return res;
}
int main()
{
    size_t m = 4, n = 4;
    m = ReadNum();
    n = ReadNum();
    size_t len1 = m + 1, len2 = n + 1;
    QPrint qout(20000000);
    size_t fft_len = min_2pow(len1 + len2 - 1);
    Complex *fft_ary = new Complex[fft_len];
    for (size_t i = 0; i < len1; i++)
    {
        int c = ReadNum();
        fft_ary[i].real(c);
    }
    for (size_t i = 0; i < len2; i++)
    {
        int c = ReadNum();
        fft_ary[i].imag(c);
    }
    fft_dif(fft_ary, fft_len, false);
    HintFloat inv = -0.5 / fft_len;
    Complex2 invx4(inv);
    for (size_t i = 0; i < fft_len; i += 2)
    {
        Complex2 tmp = fft_ary + i;
        tmp = tmp * tmp.linear_mul(invx4);
        (tmp.conj()).store(fft_ary + i);
    }
    fft_dit(fft_ary, fft_len, false);
    for (size_t i = 0; i < len1 + len2 - 1; i++)
    {
        qout << int(fft_ary[i].imag() + 0.5);
    }
    // delete[] fft_ary;
    qout.put();
}
// int main()
// {
//     constexpr size_t STR_LEN = 4005;
//     constexpr uint64_t BASE = hint::qpow(10ull, DIGIT);
//     static char out[STR_LEN];
//     // static Complex2 avx_ary[1 << 18];
//     static Complex fft_ary[1 << 10];
//     size_t len_a = 0, len_b = 0;
//     scanf("%s", out);
//     while (isdigit(out[len_a]))
//     {
//         len_a++;
//     }
//     if (len_a == 1 && out[0] == '0')
//     {
//         printf("0");
//         return 0;
//     }
//     size_t len1 = char_to_real(out, fft_ary, len_a);
//     scanf("%s", out);
//     while (isdigit(out[len_b]))
//     {
//         len_b++;
//     }
//     if (len_b == 1 && out[0] == '0')
//     {
//         printf("0");
//         return 0;
//     }
//     size_t len2 = char_to_imag(out, fft_ary, len_b);
//     size_t fft_len = min_2pow(len1 + len2 - 1);
//     fft_dif(fft_ary, fft_len, false); // 优化FFT
//     HintFloat inv = -0.5 / fft_len;
//     Complex2 invx4(inv);
//     for (size_t i = 0; i < fft_len; i++)
//     {
//         Complex tmp = fft_ary[i];
//         fft_ary[i] = std::conj(tmp * tmp) * inv;
//         // Complex2 tmp = fft_ary + i;
//         // tmp = tmp * tmp;
//         // (tmp.conj()).store(fft_ary + i);
//     }
//     fft_dit(fft_ary, fft_len, false); // 优化FFT
//     UINT_64 carry = 0;
//     size_t pos = STR_LEN - 1;
//     for (size_t i = 0; i < len1 + len2 - 1; i++)
//     {
//         carry += UINT_64(fft_ary[i].imag() + 0.5);
//         UINT_64 num = 0;
//         std::tie(carry, num) = div_mod<UINT_64>(carry, BASE);
//         // num_to_s_base10000(out + pos - DIGIT, num);
//         num_to_s(out + pos - DIGIT, num);
//         pos -= DIGIT;
//     }
//     num_to_s(out + pos - DIGIT, carry);
//     pos -= DIGIT;
//     while (out[pos] == '0')
//     {
//         pos++;
//     }
//     puts(out + pos);
// }

评测结果