提交记录 123958


用户 题目 状态 得分 用时 内存 语言 代码长度
TSKY 1004. 【模板题】高精度乘法 Accepted 100 6.259 ms 10180 KB C++14 48.60 KB
提交时间 评测时间
2026-10-03 18:58:46 2026-10-03 18:58:50
constexpr auto statement = "Do NOT modify this statement! "
                           "https://github.com/With-Sky/HintFFT "
                           "TSKY (WithSky)";

#include <complex>
#include <iostream>
#include <type_traits>
#include <cstdint>
#include <climits>
#include <cstring>
#include <immintrin.h>
#pragma GCC target("avx2,fma")

namespace hint
{
    template <typename T, size_t ALIGN = 64>
    class AlignMem{
    public:
        using Ptr = T *;
        using ConstPtr = const T *;
        ~AlignMem(){
            if (ptr){
                _mm_free(ptr);}};
        AlignMem() : ptr(nullptr), len(0) {}
        AlignMem(size_t n) : ptr(reinterpret_cast<Ptr>(_mm_malloc(n * sizeof(T), ALIGN))), len(n) {}
        AlignMem(const AlignMem &) = delete;
        AlignMem &operator=(const AlignMem &) = delete;
        T &operator[](size_t i){
            return ptr[i];}
        const T &operator[](size_t i) const{
            return ptr[i];}
        Ptr begin(){
            return ptr;}
        Ptr end(){
            return ptr + len;}
        ConstPtr begin() const{
            return ptr;}
        ConstPtr end() const{
            return ptr + len;}
        size_t size() const{
            return len;}

    private:
        T *ptr;
        size_t len;};
    template <typename YMM>
    inline void transpose64_2X4(YMM &row0, YMM &row1){
        auto t0 = _mm256_unpacklo_pd(__m256d(row0), __m256d(row1));
        auto t1 = _mm256_unpackhi_pd(__m256d(row0), __m256d(row1));
        row0 = YMM(_mm256_permute2f128_pd(t0, t1, 0x20));
        row1 = YMM(_mm256_permute2f128_pd(t0, t1, 0x31));}
    template <typename YMM>
    inline void transpose64_4X2(YMM &row0, YMM &row1){
        auto t0 = _mm256_permute2f128_pd(__m256d(row0), __m256d(row1), 0x20);
        auto t1 = _mm256_permute2f128_pd(__m256d(row0), __m256d(row1), 0x31);
        row0 = YMM(_mm256_unpacklo_pd(t0, t1));
        row1 = YMM(_mm256_unpackhi_pd(t0, t1));}

    template <typename YMM>
    inline void transpose64_4X4(YMM &row0, YMM &row1, YMM &row2, YMM &row3){
        auto t0 = _mm256_unpacklo_pd(__m256d(row0), __m256d(row1));
        auto t1 = _mm256_unpackhi_pd(__m256d(row0), __m256d(row1));
        auto t2 = _mm256_unpacklo_pd(__m256d(row2), __m256d(row3));
        auto t3 = _mm256_unpackhi_pd(__m256d(row2), __m256d(row3));

        row0 = YMM(_mm256_permute2f128_pd(t0, t2, 0x20));
        row1 = YMM(_mm256_permute2f128_pd(t1, t3, 0x20));
        row2 = YMM(_mm256_permute2f128_pd(t0, t2, 0x31));
        row3 = YMM(_mm256_permute2f128_pd(t1, t3, 0x31));}
    class Float64X4{
    public:
        using F64 = double;
        using F64X4 = Float64X4;
        Float64X4() : data(_mm256_setzero_pd()) {}
        Float64X4(__m256d in_data) : data(in_data) {}
        Float64X4(F64 in_data) : data(_mm256_set1_pd(in_data)) {}
        Float64X4(const F64 *in_data) : data(_mm256_load_pd(in_data)) {}
        F64X4 operator+(const F64X4 &other) const{
            return _mm256_add_pd(data, other.data);}
        F64X4 operator-(const F64X4 &other) const{
            return _mm256_sub_pd(data, other.data);}
        F64X4 operator*(const F64X4 &other) const{
            return _mm256_mul_pd(data, other.data);}
        F64X4 operator/(const F64X4 &other) const{
            return _mm256_div_pd(data, other.data);}
        static F64X4 fmadd(const F64X4 &a, const F64X4 &b, const F64X4 &c){
            return _mm256_fmadd_pd(a.data, b.data, c.data);}
        static F64X4 fmsub(const F64X4 &a, const F64X4 &b, const F64X4 &c){
            return _mm256_fmsub_pd(a.data, b.data, c.data);}
        template <int N>
        F64X4 permute4x64() const{
            return _mm256_permute4x64_pd(data, N);}
        F64X4 reverse() const{
            return permute4x64<0b00011011>();}
        void load(const F64 *p){
            data = _mm256_load_pd(p);}
        void load1(const F64 *p){
            data = _mm256_broadcast_sd(p);}
        void store(F64 *p) const{
            _mm256_store_pd(p, data);}
        operator __m256d() const{
            return data;}
        __m256i toI64X4() const{
            constexpr uint64_t mask = (uint64_t(1) << 52) - 1;
            constexpr uint64_t offset = (uint64_t(1) << 10) - 1;
            const __m256i f64bits = _mm256_castpd_si256(data);
            __m256i tail = _mm256_and_si256(f64bits, _mm256_set1_epi64x(mask));
            tail = _mm256_or_si256(tail, _mm256_set1_epi64x(mask + 1));
            __m256i exp = _mm256_srli_epi64(f64bits, 52);
            exp = _mm256_sub_epi64(_mm256_set1_epi64x(offset + 52), exp);
            return _mm256_srlv_epi64(tail, exp);}

    private:
        __m256d data;};

    struct Complex64X4{
        using C64X4 = Complex64X4;
        using F64X4 = Float64X4;
        using F64 = double;
        Complex64X4() {}
        Complex64X4(F64X4 real, F64X4 imag) : real(real), imag(imag) {}
        Complex64X4(const F64 *p) : real(p), imag(p + 4) {}
        Complex64X4(const F64 *p_real, const F64 *p_imag) : real(p_real), imag(p_imag) {}
        C64X4 operator+(const C64X4 &other) const{
            return C64X4(real + other.real, imag + other.imag);}
        C64X4 operator-(const C64X4 &other) const{
            return C64X4(real - other.real, imag - other.imag);}
        C64X4 operator*(const F64X4 &other) const{
            return C64X4(real * other, imag * other);}
        C64X4 mul(const C64X4 &other) const{
            const F64X4 ii = imag * other.imag;
            const F64X4 ri = real * other.imag;
            const F64X4 r = F64X4::fmsub(real, other.real, ii);
            const F64X4 i = F64X4::fmadd(imag, other.real, ri);
            return C64X4(r, i);}
        C64X4 mulConj(const C64X4 &other) const{
            const F64X4 ii = imag * other.imag;
            const F64X4 ri = real * other.imag;
            const F64X4 r = F64X4::fmadd(real, other.real, ii);
            const F64X4 i = F64X4::fmsub(imag, other.real, ri);
            return C64X4(r, i);}
        C64X4 reverse() const{
            return C64X4(real.reverse(), imag.reverse());}
        void set1(F64 real_in, F64 imag_in){
            real = F64X4(real_in);
            imag = F64X4(imag_in);}
        template <typename T>
        void load(const T *p, std::false_type){
            this->load(p);}
        template <typename T>
        void load(const T *p, std::true_type){
            this->load(p);
            *this = this->toRRIIPermu();}
        template <typename T>
        void load(const T *p){
            real.load(reinterpret_cast<const F64 *>(p));
            imag.load(reinterpret_cast<const F64 *>(p) + 4);}
        void load1(const F64 *real_p, const F64 *imag_p){
            real.load1(real_p);
            imag.load1(imag_p);}

        template <typename T>
        void store(T *p, std::false_type) const{
            this->store(p);}
        template <typename T>
        void store(T *p, std::true_type) const{
            this->toRIRIPermu().store(p);}
        template <typename T>
        void store(T *p) const{
            real.store(reinterpret_cast<F64 *>(p));
            imag.store(reinterpret_cast<F64 *>(p) + 4);}
        C64X4 toRIRIPermu() const{
            C64X4 res = *this;
            transpose64_2X4(res.real, res.imag);
            return res;}
        C64X4 toRRIIPermu() const{
            C64X4 res = *this;
            transpose64_4X2(res.real, res.imag);
            return res;}
        C64X4 transToI64(std::false_type) const{
            return *this;}
        C64X4 transToI64(std::true_type) const{
            constexpr int64_t F1_2 = 4602678819172646912;
            auto F1_2X4 = F64X4(__m256d(_mm256_set1_epi64x(F1_2)));
            auto real_i64 = (real + F1_2X4).toI64X4();
            auto imag_i64 = (imag + F1_2X4).toI64X4();
            return C64X4(__m256d(real_i64), __m256d(imag_i64));}
        F64X4 real, imag;};

    using Float32 = float;
    using Float64 = double;
    using FloatLong = long double;
    constexpr FloatLong HINT_PIL = 3.141592653589793238462643383279L;
    constexpr Float64 HINT_PI = HINT_PIL;
    constexpr Float64 HINT_2PI = HINT_PI * 2;
    constexpr Float64 COS_PI_8 = 0.707106781186547524400844;
    template <typename T>
    constexpr T int_floor2(T n){
        constexpr int bits = sizeof(n) * 8;
        for (int i = 1; i < bits; i *= 2){
            n |= (n >> i);}
        return (n >> 1) + 1;}

    template <typename T>
    constexpr T int_ceil2(T n){
        constexpr int bits = sizeof(n) * 8;
        n--;
        for (int i = 1; i < bits; i *= 2){
            n |= (n >> i);}
        return n + 1;}

    template <typename IntTy>
    constexpr bool is_2pow(IntTy n){
        return n != 0 && (n & (n - 1)) == 0;}
    template <typename T>
    constexpr int hint_log2(T n){
        constexpr int bits = sizeof(n) * 8;
        int l = -1, r = bits;
        while ((l + 1) != r){
            int mid = (l + r) / 2;
            if ((T(1) << mid) > n){
                r = mid;}
            else{
                l = mid;}}
        return l;}
    constexpr FloatLong sin_poly(FloatLong x)
    {
        if (x < 0)
        {
            return -sin_poly(-x);
        }
        if (x > HINT_PIL)
        {
            return -sin_poly(x - HINT_PIL);
        }
        if (x > HINT_PIL / 2)
        {
            return sin_poly(HINT_PIL - x);
        }
        const FloatLong xl = x, x2 = xl * xl, x4 = x2 * x2, x6 = x4 * x2, x8 = x4 * x4, x10 = x6 * x4, x12 = x6 * x6, x14 = x8 * x6, x16 = x8 * x8, x18 = x10 * x8, x20 = x10 * x10;
        return xl * (1.0L - x2 / 6.0L + x4 / 120.0L - x6 / 5040.0L + x8 / 362880.0L - x10 / 39916800.0L + x12 / 6227020800.0L - x14 / 1307674368000.0L + x16 / 355687428096000.0L - x18 / 121645100408832000.0L + x20 / 51090942171709440000.0L);
    }

    constexpr FloatLong cos_poly(FloatLong x)
    {
        if (x < 0)
        {
            x = -x;
        }
        return sin_poly(HINT_PIL / 2.0 - x);
    }

    constexpr uint32_t crc32(const char *str){
        uint32_t crc = 0xFFFFFFFF;
        while (*str != '\0'){
            crc ^= *str;
            for (int i = 0; i < 8; ++i){
                crc = (crc >> 1) ^ (0 - (crc & 1)) & 0xEDB88320;}
            str++;}
        return ~crc;}
    namespace transform{
        template <typename T>
        inline void transform2(T &sum, T &diff){
            T temp0 = sum, temp1 = diff;
            sum = temp0 + temp1;
            diff = temp0 - temp1;}
        namespace fft{
            using F64 = Float64;
            using C64 = std::complex<F64>;
            using F64X4 = Float64X4;
            using C64X4 = Complex64X4;
            template <typename Float>
            constexpr void initOmega(Float *table, size_t fft_len, size_t table_len, int factor, int stride)
            {
                const Float theta = -HINT_2PI * factor / fft_len;
                for (size_t begin = 0, index = 0; begin < table_len * 2; begin += stride * 2)
                {
                    for (size_t j = 0; j < stride; j++, index++)
                    {
                        table[begin + j] = cos_poly(theta * index);
                        table[begin + j + stride] = sin_poly(theta * index);
                    }
                }
            }
            template <typename Float, size_t OMEGA_LEN>
            class TableFix
            {
                alignas(64) Float table[OMEGA_LEN * 2]{};

            public:
                constexpr TableFix() = default;
                constexpr TableFix(size_t fft_len, size_t factor, size_t stride)
                {
                    init(fft_len, factor, stride);
                }
                constexpr void init(size_t fft_len, size_t factor, size_t stride)
                {
                    initOmega(table, fft_len, OMEGA_LEN, factor, stride);
                }
                constexpr const Float &operator[](size_t index) const
                {
                    return table[index];
                }
            };
            template <typename Float, int LOG_BEGIN, int LOG_END, int DIV>
            class TableFixMulti
            {
                static constexpr size_t END_LEN = (size_t(1) << LOG_END) / DIV, BEGIN_LEN = (size_t(1) << LOG_BEGIN) / DIV, TABLE_CPX_LEN = END_LEN * 2 - BEGIN_LEN;
                alignas(64) Float table[TABLE_CPX_LEN * 2]{};

            public:
                constexpr TableFixMulti() = default;
                constexpr TableFixMulti(size_t factor, size_t stride = 4)
                {
                    init(factor, stride);
                }
                constexpr void init(size_t factor, size_t stride)
                {
                    for (int log_len = LOG_BEGIN; log_len <= LOG_END; log_len++)
                    {
                        size_t len = size_t(1) << log_len, cpx_len = len / DIV;
                        auto it = getBeginLog(log_len);
                        initOmega(it, len, cpx_len, factor, stride);
                    }
                }
                constexpr const Float *getBeginLog(int log_rank) const
                {
                    return getBegin(size_t(1) << log_rank);
                }
                constexpr Float *getBeginLog(int log_rank)
                {
                    return getBegin(size_t(1) << log_rank);
                }
                constexpr const Float *getBegin(size_t rank) const
                {
                    return &table[rank * 2 / DIV - BEGIN_LEN * 2];
                }
                constexpr Float *getBegin(size_t rank)
                {
                    return &table[rank * 2 / DIV - BEGIN_LEN * 2];
                }
            };

            template <int LOW_LOG_LEN>
            struct HighLowPtrC64XX4
            {
                static constexpr int CX4_LOG_LEN = LOW_LOG_LEN - 2;
                static constexpr size_t LOW_LEN = size_t(1) << CX4_LOG_LEN, MASK = LOW_LEN - 1;
                const C64X4 *low;
                const C64 *high;

                C64X4 operator[](size_t i) const
                {
                    C64X4 hi;
                    auto p = reinterpret_cast<const F64 *>(&high[i >> CX4_LOG_LEN]);
                    hi.load1(p, p + 1);
                    return low[i & MASK].mul(hi);
                }
            };

            template <int LOG_BEGIN, int LOG_END, int LOG_LOW_BYTE, int DIV>
            class TableSqrtC64X4
            {
            public:
                static constexpr int LOG_LOW_LEN = LOG_LOW_BYTE - 4; // C64 len
                static constexpr size_t BEGIN_RANK = size_t(1) << LOG_BEGIN, BEGIN_LEN = BEGIN_RANK / DIV;
                static constexpr size_t TABLE_COUNT = LOG_END - LOG_BEGIN + 1;
                using TableLow = TableFix<Float64, size_t(1) << LOG_LOW_LEN>;
                using TableHigh = TableFixMulti<Float64, LOG_BEGIN - LOG_LOW_LEN, LOG_END - LOG_LOW_LEN, DIV>;
                using Ptr = HighLowPtrC64XX4<LOG_LOW_LEN>;

                TableLow table_low[TABLE_COUNT]{};
                TableHigh table_high;

            public:
                constexpr TableSqrtC64X4(int factor)
                {
                    for (int i = 0; i < TABLE_COUNT; i++)
                    {
                        table_low[i].init(size_t(1) << (LOG_BEGIN + i), factor, 4);
                    }
                    table_high.init(factor, 1);
                }
                constexpr Ptr getBeginLog(int log_rank) const
                {
                    return Ptr{reinterpret_cast<const C64X4 *>(&table_low[log_rank - LOG_BEGIN][0]),
                               reinterpret_cast<const C64 *>(table_high.getBeginLog(log_rank - LOG_LOW_LEN))};
                }
            };
            struct FFT{
                template <typename Float>
                static void trans2MulI(Float &r0, Float &i0, Float &r1, Float &i1){
                    auto temp = r1;
                    r1 = r0 + i1;
                    r0 = r0 - i1;
                    i1 = i0 - temp;
                    i0 = i0 + temp;}
                template <typename Float>
                static void trans2MulNegI(Float &r0, Float &i0, Float &r1, Float &i1){
                    auto temp = r1;
                    r1 = r0 - i1;
                    r0 = r0 + i1;
                    i1 = i0 + temp;
                    i0 = i0 - temp;}
                template <typename Float>
                static void dif4(Float &r0, Float &i0, Float &r1, Float &i1, Float &r2, Float &i2, Float &r3, Float &i3){
                    difSplit(r0, i0, r1, i1, r2, i2, r3, i3);
                    transform2(r0, r1);
                    transform2(i0, i1);}
                template <typename Float>
                static void idit4(Float &r0, Float &i0, Float &r1, Float &i1, Float &r2, Float &i2, Float &r3, Float &i3){
                    transform2(r0, r1);
                    transform2(i0, i1);
                    iditSplit(r0, i0, r1, i1, r2, i2, r3, i3);}
                template <typename Float>
                static void difSplit(Float &r0, Float &i0, Float &r1, Float &i1, Float &r2, Float &i2, Float &r3, Float &i3){
                    transform2(r0, r2);
                    transform2(i0, i2);
                    transform2(r1, r3);
                    transform2(i1, i3);
                    trans2MulNegI(r2, i2, r3, i3);}
                template <typename Float>
                static void iditSplit(Float &r0, Float &i0, Float &r1, Float &i1, Float &r2, Float &i2, Float &r3, Float &i3){
                    transform2(r2, r3);
                    transform2(i2, i3);
                    transform2(r0, r2);
                    transform2(i0, i2);
                    trans2MulI(r1, i1, r3, i3);}};
            struct FFTAVX : public FFT{
                static constexpr int LOG_SHORT = 10, LOG_MID = 25 - crc32(statement) % 15, LOG_MAX = 18, LOG_CACHE = 11;
                static constexpr size_t SHORT_LEN = size_t(1) << LOG_SHORT, MID_LEN = size_t(1) << LOG_MID, MAX_LEN = size_t(1) << LOG_MAX;
                using TableFix4 = const TableFix<Float64, 4>;
                using TableFix8 = const TableFix<Float64, 8>;
                using TableMulti1 = const TableFixMulti<Float64, 6, LOG_MID, 4>;
                using TableMulti2 = const TableFixMulti<Float64, 6, LOG_SHORT + 1, 4>;
                using TableMulti3 = const TableFixMulti<Float64, 6, LOG_SHORT, 4>;
                using TableSqrt = const TableSqrtC64X4<LOG_MID + 1, LOG_MAX, 13, 4>;
                static constexpr TableFix4 table_8{8, 1, 4}, table_16_1{16, 1, 4}, table_16_3{16, 3, 4};
                static constexpr TableFix8 table_32_1{32, 1, 4}, table_32_3{32, 3, 4};
                static constexpr TableMulti2 multi_table_2{2, 4};
                static constexpr TableMulti3 multi_table_3{3, 4};
                static constexpr TableMulti1 multi_table_1{1, 4};
                static constexpr TableSqrt sqrt_table_1{1};
                static constexpr const Float64 *it8 = &table_8[0], *it16_1 = &table_16_1[0], *it16_3 = &table_16_3[0], *it32_1 = &table_32_1[0], *it32_3 = &table_32_3[0];
                static void dif4x4(F64X4 &r0, F64X4 &i0, F64X4 &r1, F64X4 &i1, F64X4 &r2, F64X4 &i2, F64X4 &r3, F64X4 &i3){
                    transpose64_4X4(r0, r1, r2, r3);
                    transpose64_4X4(i0, i1, i2, i3);
                    dif4(r0, i0, r1, i1, r2, i2, r3, i3);
                    transpose64_4X4(r0, r1, r2, r3);
                    transpose64_4X4(i0, i1, i2, i3);}
                static void idit4x4(F64X4 &r0, F64X4 &i0, F64X4 &r1, F64X4 &i1, F64X4 &r2, F64X4 &i2, F64X4 &r3, F64X4 &i3){
                    transpose64_4X4(r0, r1, r2, r3);
                    transpose64_4X4(i0, i1, i2, i3);
                    idit4(r0, i0, r1, i1, r2, i2, r3, i3);
                    transpose64_4X4(r0, r1, r2, r3);
                    transpose64_4X4(i0, i1, i2, i3);}
                static void dif8x2(C64X4 &c0, C64X4 &c1, C64X4 &c2, C64X4 &c3){
                    C64X4 omega(it8);
                    transform2(c0, c1);
                    transform2(c2, c3);
                    c1 = c1.mul(omega), c3 = c3.mul(omega);
                    dif4x4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);}
                static void idit8x2(C64X4 &c0, C64X4 &c1, C64X4 &c2, C64X4 &c3){
                    C64X4 omega(it8);
                    idit4x4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                    c1 = c1.mulConj(omega), c3 = c3.mulConj(omega);
                    transform2(c0, c1);
                    transform2(c2, c3);}
                static void dif16(Float64 in_out[]){
                    auto p = reinterpret_cast<C64X4 *>(in_out);
                    C64X4 c0 = p[0], c1 = p[1], c2 = p[2], c3 = p[3];
                    dif4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                    c1 = c1.mul(C64X4(it8)), c2 = c2.mul(C64X4(it16_1)), c3 = c3.mul(C64X4(it16_3));
                    dif4x4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                    p[0] = c0, p[1] = c1, p[2] = c2, p[3] = c3;}
                static void idit16(Float64 in_out[]){
                    auto p = reinterpret_cast<C64X4 *>(in_out);
                    C64X4 c0 = p[0], c1 = p[1], c2 = p[2], c3 = p[3], omega;
                    idit4x4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                    c1 = c1.mulConj(C64X4(it8)), c2 = c2.mulConj(C64X4(it16_1)), c3 = c3.mulConj(C64X4(it16_3));
                    idit4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                    p[0] = c0, p[1] = c1, p[2] = c2, p[3] = c3;}
                static void dif32(Float64 in_out[]){
                    auto p = reinterpret_cast<C64X4 *>(in_out);
                    C64X4 c0 = p[0], c1 = p[2], c2 = p[4], c3 = p[6];
                    difSplit(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                    c2 = c2.mul(C64X4(it32_1)), c3 = c3.mul(C64X4(it32_3));
                    p[0] = c0, p[2] = c1, p[4] = c2, p[6] = c3;
                    c0 = p[1], c1 = p[3], c2 = p[5], c3 = p[7];
                    difSplit(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                    c2 = c2.mul(C64X4(it32_1 + 8)), c3 = c3.mul(C64X4(it32_3 + 8));
                    p[1] = c0, p[3] = c1, c0 = p[4], c1 = p[6];
                    dif8x2(c0, c2, c1, c3);
                    p[4] = c0, p[5] = c2, p[6] = c1, p[7] = c3;
                    dif16(in_out);}
                static void idit32(Float64 in_out[]){
                    idit16(in_out);
                    auto p = reinterpret_cast<C64X4 *>(in_out);
                    C64X4 c0 = p[4], c1 = p[5], c2 = p[6], c3 = p[7];
                    idit8x2(c0, c1, c2, c3);
                    p[5] = c1, p[7] = c3, c1 = p[0], c3 = p[2];
                    c0 = c0.mulConj(C64X4(it32_1)), c2 = c2.mulConj(C64X4(it32_3));
                    iditSplit(c1.real, c1.imag, c3.real, c3.imag, c0.real, c0.imag, c2.real, c2.imag);
                    p[0] = c1, p[2] = c3, p[4] = c0, p[6] = c2;
                    c0 = p[1], c1 = p[3], c2 = p[5], c3 = p[7];
                    c2 = c2.mulConj(C64X4(it32_1 + 8)), c3 = c3.mulConj(C64X4(it32_3 + 8));
                    iditSplit(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                    p[1] = c0, p[3] = c1, p[5] = c2, p[7] = c3;}
                template <typename F32, typename F16>
                static void fftTiny(Float64 in_out[], size_t float_len, F32 &&func32, F16 &&func16){
                    if (hint_log2(float_len / 2) % 2 == 0)
                    {
                        for (auto end = in_out + float_len; in_out < end; in_out += 32)
                        {
                            func16(in_out);}}
                    else
                    {
                        for (auto end = in_out + float_len; in_out < end; in_out += 64)
                        {
                            func32(in_out);}}}
                static void difIter(Float64 in_out[], size_t float_len){
                    size_t fft_len = float_len / 2;
                    C64X4 c0, c1, c2, c3;
                    size_t stride = fft_len / 2;
                    auto it0 = in_out, it1 = it0 + stride, it2 = it1 + stride, it3 = it2 + stride;
                    for (size_t rank = fft_len; rank >= 64; rank /= 4)
                    {
                        stride = rank / 2;
                        for (auto begin = in_out, end = in_out + float_len; begin < end; begin += rank * 2)
                        {
                            auto table1 = multi_table_2.getBegin(rank * 2), table2 = multi_table_2.getBegin(rank), table3 = multi_table_3.getBegin(rank);
                            it0 = begin, it1 = it0 + stride, it2 = it1 + stride, it3 = it2 + stride;
                            for (; it0 < begin + stride; it0 += 8, it1 += 8, it2 += 8, it3 += 8, table1 += 8, table2 += 8, table3 += 8)
                            {
                                c0 = it0, c1 = it1, c2 = it2, c3 = it3;
                                dif4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                                c1 = c1.mul(C64X4(table2)), c2 = c2.mul(C64X4(table1)), c3 = c3.mul(C64X4(table3));
                                c0.store(it0), c1.store(it1), c2.store(it2), c3.store(it3);
                            }}}
                    fftTiny(in_out, float_len, dif32, dif16);}
                static void iditIter(Float64 in_out[], size_t float_len){
                    size_t fft_len = float_len / 2;
                    size_t rank = hint_log2(fft_len) % 2 == 0 ? 64 : 128;
                    fftTiny(in_out, float_len, idit32, idit16);
                    for (; rank <= fft_len; rank *= 4)
                    {
                        const size_t stride = rank / 2;
                        for (auto begin = in_out, end = in_out + float_len; begin < end; begin += rank * 2)
                        {
                            auto table1 = multi_table_2.getBegin(rank * 2), table2 = multi_table_2.getBegin(rank), table3 = multi_table_3.getBegin(rank);
                            auto it0 = begin, it1 = it0 + stride, it2 = it1 + stride, it3 = it2 + stride;
                            for (; it0 < begin + stride; it0 += 8, it1 += 8, it2 += 8, it3 += 8, table1 += 8, table2 += 8, table3 += 8)
                            {
                                C64X4 c0 = it0, c1 = it1, c2 = it2, c3 = it3;
                                c1 = c1.mulConj(C64X4(table2)), c2 = c2.mulConj(C64X4(table1)), c3 = c3.mulConj(C64X4(table3));
                                idit4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);
                                c0.store(it0), c1.store(it1), c2.store(it2), c3.store(it3);
                            }}}}
#define difLayer(dif_func, in_out, stride, table)                                                                   \
    do                                                                                                              \
    {                                                                                                               \
        auto it0 = in_out, it1 = in_out + stride, it2 = it1 + stride, it3 = it2 + stride;                           \
        size_t indx = 0;                                                                                            \
        for (auto end = it1; FROM_RIRI_PERM && it0 < end; it0 += 8, it1 += 8, it2 += 8, it3 += 8, indx++)           \
        {                                                                                                           \
            C64X4 c0, c1, c2, c3, omega1, omega2;                                                                   \
            c0.load(it0, FromRIRI{}), c1.load(it1, FromRIRI{}), c2 = c0,c3 = c1;                                    \
            transform2(c0,c1);                                                                                      \
            trans2MulNegI(c2.real,c2.imag,c3.real,c3.imag);                                                         \
            omega1 = table[indx], c2 = c2.mul(omega1);                                                              \
            omega2 = omega1.mul(omega1), c1 = c1.mul(omega2);                                                       \
            c3 = c3.mul(omega2.mul(omega1));                                                                        \
            c0.store(it0), c1.store(it1), c2.store(it2), c3.store(it3);                                             \
        }                                                                                                           \
        for (auto end = it1; (!FROM_RIRI_PERM) && it0 < end; it0 += 8, it1 += 8, it2 += 8, it3 += 8, indx++)        \
        {                                                                                                           \
            C64X4 c0 = it0, c1 = it1, c2 = it2, c3 = it3, omega1, omega2;                                           \
            dif4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);                           \
            omega1 = table[indx], c2 = c2.mul(omega1);                                                              \
            omega2 = omega1.mul(omega1), c1 = c1.mul(omega2);                                                       \
            c3 = c3.mul(omega2.mul(omega1));                                                                        \
            c0.store(it0), c1.store(it1), c2.store(it2), c3.store(it3);                                             \
        }                                                                                                           \
        dif_func(in_out, stride);                                                                                   \
        dif_func(in_out + stride, stride);                                                                          \
        dif_func(in_out + stride * 2, stride);                                                                      \
        dif_func(in_out + stride * 3, stride);                                                                      \
    } while (0)
#define iditLayer(idit_func, in_out, stride, table)                                                                             \
    do                                                                                                                          \
    {                                                                                                                           \
        idit_func(in_out, stride);                                                                                              \
        idit_func(in_out + stride, stride);                                                                                     \
        idit_func(in_out + stride * 2, stride);                                                                                 \
        idit_func(in_out + stride * 3, stride);                                                                                 \
        auto it0 = in_out, it1 = in_out + stride, it2 = it1 + stride, it3 = it2 + stride;                                       \
        size_t indx = 0;                                                                                                        \
        for (auto end = it1; it0 < end; it0 += 8, it1 += 8, it2 += 8, it3 += 8, indx++)                                         \
        {                                                                                                                       \
            C64X4 c0 = it0, c1 = it1, c2 = it2, c3 = it3, omega1, omega2;                                                       \
            omega1 = table[indx], c2 = c2.mulConj(omega1);                                                                      \
            omega2 = omega1.mul(omega1), c1 = c1.mulConj(omega2);                                                               \
            c3 = c3.mulConj(omega2.mul(omega1));                                                                                \
            idit4(c0.real, c0.imag, c1.real, c1.imag, c2.real, c2.imag, c3.real, c3.imag);                                      \
            c0 = c0.transToI64(ToI64{}), c1 = c1.transToI64(ToI64{}), c2 = c2.transToI64(ToI64{}), c3 = c3.transToI64(ToI64{}); \
            c0.store(it0, ToRIRI{}), c1.store(it1, ToRIRI{}), c2.store(it2, ToRIRI{}), c3.store(it3, ToRIRI{});                 \
        }                                                                                                                       \
    } while (0)
                template <bool FROM_RIRI_PERM = false>
                static void difRecMid(Float64 in_out[], size_t float_len){
                    const size_t fft_len = float_len / 2;
                    if (fft_len <= SHORT_LEN)
                    {
                        difIter(in_out, float_len);
                        return;}
                    using FromRIRI = std::integral_constant<bool, FROM_RIRI_PERM>;
                    auto table1 = reinterpret_cast<const C64X4 *>(multi_table_1.getBegin(fft_len));
                    const size_t stride = float_len / 4;
                    difLayer(difRecMid, in_out, stride, table1);}
                template <bool TO_RIRI_PERM = false, bool TO_INT64 = false>
                static void iditRecMid(Float64 in_out[], size_t float_len){
                    const size_t fft_len = float_len / 2;
                    if (fft_len <= SHORT_LEN)
                    {
                        iditIter(in_out, float_len);
                        return;}
                    using ToRIRI = std::integral_constant<bool, TO_RIRI_PERM>;
                    using ToI64 = std::integral_constant<bool, TO_INT64>;
                    const size_t stride = float_len / 4;
                    auto table1 = reinterpret_cast<const C64X4 *>(multi_table_1.getBegin(fft_len));
                    iditLayer(iditRecMid, in_out, stride, table1);}

                template <bool FROM_RIRI_PERM = false>
                static void difRecLong(Float64 in_out[], size_t float_len){
                    const size_t fft_len = float_len / 2;
                    if (fft_len <= MID_LEN)
                    {
                        difRecMid<FROM_RIRI_PERM>(in_out, float_len);
                        return;}
                    using FromRIRI = std::integral_constant<bool, FROM_RIRI_PERM>;
                    const auto table1 = sqrt_table_1.getBeginLog(hint_log2(fft_len));
                    const size_t stride = float_len / 4;
                    difLayer(difRecLong, in_out, stride, table1);}
                template <bool TO_RIRI_PERM = false, bool TO_INT64 = false>
                static void iditRecLong(Float64 in_out[], size_t float_len){
                    const size_t fft_len = float_len / 2;
                    if (fft_len <= MID_LEN)
                    {
                        iditRecMid<TO_RIRI_PERM, TO_INT64>(in_out, float_len);
                        return;}
                    using ToRIRI = std::integral_constant<bool, TO_RIRI_PERM>;
                    using ToI64 = std::integral_constant<bool, TO_INT64>;
                    const size_t stride = float_len / 4;
                    const auto table1 = sqrt_table_1.getBeginLog(hint_log2(fft_len));
                    iditLayer(iditRecLong, in_out, stride, table1);}};
#undef difLayer
#undef iditLayer

            constexpr int FFTAVX::LOG_SHORT, FFTAVX::LOG_MID, FFTAVX::LOG_MAX, FFTAVX::LOG_CACHE;
            constexpr size_t FFTAVX::SHORT_LEN, FFTAVX::MID_LEN, FFTAVX::MAX_LEN;
            constexpr FFTAVX::TableFix4 FFTAVX::table_8, FFTAVX::table_16_1, FFTAVX::table_16_3;
            constexpr FFTAVX::TableFix8 FFTAVX::table_32_1, FFTAVX::table_32_3;
            constexpr FFTAVX::TableMulti2 FFTAVX::multi_table_2;
            constexpr FFTAVX::TableMulti3 FFTAVX::multi_table_3;
            constexpr FFTAVX::TableMulti1 FFTAVX::multi_table_1;
            constexpr FFTAVX::TableSqrt FFTAVX::sqrt_table_1;

            constexpr uint32_t bitrev32(uint32_t n){
                constexpr uint32_t mask55 = 0x55555555;
                constexpr uint32_t mask33 = 0x33333333;
                constexpr uint32_t mask0f = 0x0f0f0f0f;
                constexpr uint32_t maskff = 0x00ff00ff;
                n = ((n & mask55) << 1) | ((n >> 1) & mask55);
                n = ((n & mask33) << 2) | ((n >> 2) & mask33);
                n = ((n & mask0f) << 4) | ((n >> 4) & mask0f);
                n = ((n & maskff) << 8) | ((n >> 8) & maskff);
                return (n << 16) | (n >> 16);}
            constexpr uint32_t bitrev(uint32_t n, int len){
                return bitrev32(n) >> (32 - len);}
            template <int MAX_LOG_LEN, int DIV>
            class BinRevTableC64X4HP{
            public:
                static constexpr int LOG_BLOCK = 2, BLOCK = 1 << LOG_BLOCK;
                static constexpr size_t MAX_LEN = size_t(1) << MAX_LOG_LEN;

                struct Unit{
                    C64 units[MAX_LOG_LEN]{};
                    F64 block[BLOCK * 2]{};
                    Unit()
                    {
                        constexpr F64 factor = F64(1) / DIV;
                        for (int i = 0; i < MAX_LOG_LEN; i++)
                        {
                            units[i] = getOmega(size_t(1) << (i + 1), 1, factor);}
                        block[0] = 1, block[BLOCK] = 0;
                        for (int i = 1; i < BLOCK; i++)
                        {
                            C64 omega = getOmega(BLOCK, bitrev(i, LOG_BLOCK), factor);
                            block[i] = omega.real(), block[i + BLOCK] = omega.imag();}}};

                BinRevTableC64X4HP() : index(0), pop(0){
                    std::memcpy(table, unit_table.block, sizeof(unit_table.block));}
                void reset(size_t i = 0){
                    if (i == 0)
                    {
                        pop = 0, index = i;
                        return;}
                    pop = 1, index = i / BLOCK;
                    int zero = __builtin_ctzll(index);
                    auto fp = reinterpret_cast<const F64 *>(&unit_table.units[zero + 2]);
                    table[1].load1(fp, fp + 1);
                    table[1] = table[1].mul(table[0]);}
                C64X4 iterate(){
                    C64X4 res = table[pop], unit4;
                    index++;
                    int zero = __builtin_ctzll(index);
                    auto fp = reinterpret_cast<const F64 *>(&unit_table.units[zero + 2]);
                    unit4.load1(fp, fp + 1);
                    pop -= zero;
                    table[pop + 1] = table[pop].mul(unit4);
                    pop++;
                    return res;}

                static C64 getOmega(size_t n, size_t index, F64 factor = 1){
                    F64 theta = -HINT_2PI * index / n;
                    return std::polar<F64>(1, theta * factor);}

            private:
                alignas(64) static const Unit unit_table;
                alignas(64) C64X4 table[MAX_LOG_LEN];
                size_t index;
                int pop;
                int log_max_iter, log_fft_len;};
            template <int MAX_LOG_LEN, int DIV>
            const typename BinRevTableC64X4HP<MAX_LOG_LEN, DIV>::Unit BinRevTableC64X4HP<MAX_LOG_LEN, DIV>::unit_table;
            template <size_t RI_DIFF = 1, typename FloatTy>
            inline void dot_rfft(FloatTy *inout0, FloatTy *inout1, const FloatTy *in0, const FloatTy *in1,
                                 const std::complex<FloatTy> &omega, const FloatTy inv = 1){
                using Complex = std::complex<FloatTy>;
                auto addConj = [](Complex c0, Complex c1){ return Complex(c0.real() + c1.real(), c0.imag() - c1.imag()); };
                Complex x0(inout0[0], inout0[RI_DIFF]), x1(inout1[0], inout1[RI_DIFF]),
                    y0(in0[0], in0[RI_DIFF]), y1(in1[0], in1[RI_DIFF]);
                auto t0 = x0 * y0, t1 = x1 * y1, xy0 = addConj(x0, x1), xy1 = addConj(y0, y1);
                auto t2 = xy0 * xy1;
                y1 = addConj(t0, t1);
                x1 = (y1 + y1 - t2) * omega * omega;
                const auto inv2 = inv + inv;
                x0 = (t2 - x1) * inv, x1 = Complex(t0.real() - t1.real(), t0.imag() + t1.imag()) * inv2;
                Complex out0 = x0 + x1, out1(x0.real() - x1.real(), x1.imag() - x0.imag());
                inout0[0] = out0.real(), inout0[RI_DIFF] = out0.imag();
                inout1[0] = out1.real(), inout1[RI_DIFF] = out1.imag();}
            inline void dot_rfftX4(F64 *inout0, F64 *inout1, const F64 *in0, const F64 *in1, const C64X4 &omega, const F64X4 &inv){
                auto addConj = [](const C64X4 &x0, const C64X4 &x1){
                    return C64X4(x0.real + x1.real, x0.imag - x1.imag);};
                C64X4 x0 = inout0, x1 = inout1, y0 = in0, y1 = in1;
                x1 = x1.reverse();
                y1 = y1.reverse();
                C64X4 t0 = x0.mul(y0), t1 = x1.mul(y1);
                C64X4 xy0 = addConj(x0, x1), xy1 = addConj(y0, y1);
                C64X4 t2 = xy0.mul(xy1);
                y1 = addConj(t0, t1);
                x1 = (y1 + y1 - t2).mul(omega);
                const F64X4 inv2 = inv + inv;
                x0 = (t2 - x1) * inv, x1 = C64X4(t0.real - t1.real, t0.imag + t1.imag) * inv2;
                C64X4 out0 = x0 + x1, out1(x0.real - x1.real, x1.imag - x0.imag);
                out0.store(inout0), out1.reverse().store(inout1);}

            inline void real_dot_binrev4(Float64 in_out[], Float64 in[], size_t float_len){
                Float64 inv = 2.0 / float_len;{
                    auto r0 = in_out[0], i0 = in_out[4], r1 = in[0], i1 = in[4];
                    transform2(r0, i0);
                    transform2(r1, i1);
                    r0 *= r1, i0 *= i1;
                    transform2(r0, i0);
                    in_out[0] = r0 * 0.5 * inv, in_out[4] = i0 * 0.5 * inv;}
                auto temp = C64(in_out[1], in_out[5]) * C64(in[1], in[5]) * inv;
                in_out[1] = temp.real(), in_out[5] = temp.imag();
                inv /= 4;
                dot_rfft<4>(&in_out[2], &in_out[3], &in[2], &in[3], C64(COS_PI_8, -COS_PI_8), inv);
                constexpr Float64 COS_16_1 = 0.92387953251128675612818318939;
                constexpr Float64 SIN_16_1 = 0.38268343236508977172845998403;
                dot_rfft<4>(&in_out[8], &in_out[11], &in[8], &in[11], C64(COS_16_1, -SIN_16_1), inv);
                dot_rfft<4>(&in_out[9], &in_out[10], &in[9], &in[10], C64(-SIN_16_1, -COS_16_1), inv);
                const Float64X4 inv4 = F64X4(0.5 / float_len);
                BinRevTableC64X4HP<19, 1> table;
                for (size_t begin = 16; begin < float_len; begin *= 2){
                    table.reset(begin / 2);
                    auto it0 = in_out + begin, it1 = it0 + begin - 8, it2 = in + begin, it3 = it2 + begin - 8;
                    for (; it0 < it1; it0 += 8, it1 -= 8, it2 += 8, it3 -= 8)
                    {
                        dot_rfftX4(it0, it1, it2, it3, table.iterate(), inv4);}}}
            template <bool TO_INT = false>
            inline void real_conv_avx(F64 *in_out1, F64 *in2, size_t float_len){
                FFTAVX::difRecLong<true>(in_out1, float_len);
                FFTAVX::difRecLong<true>(in2, float_len);
                real_dot_binrev4(in_out1, in2, float_len);
                FFTAVX::iditRecLong<true, TO_INT>(in_out1, float_len);}}}}
namespace string_util
{
    using namespace hint;
    using namespace transform;
    using namespace fft;
    class ItoStrBase10000{
    private:
        uint32_t table[10000]{};

    public:
        static constexpr uint32_t itosbase10000(uint32_t num){
            uint32_t res = (num / 1000 % 10) | ((num / 100 % 10) << 8) |
                           ((num / 10 % 10) << 16) | ((num % 10) << 24);
            return res + '0' * 0x1010101;}
        constexpr ItoStrBase10000(){
            for (size_t i = 0; i < 10000; i++){
                table[i] = itosbase10000(i);}}
        void tostr(char *str, uint32_t num) const{
            std::memcpy(str, &table[num], sizeof(num));}
        uint32_t tostr(uint32_t num) const{
            return table[num];}};
    constexpr ItoStrBase10000 itosbase10000{};
    template <typename T>
    void fill_zero(T *begin, T *end){
        std::memset(begin, 0, (end - begin) * sizeof(T));}

    size_t digitlen_avx2(const char *str){
        auto ptr = str;
        auto zero_vec = _mm256_set1_epi8('0');
        for (;; ptr += 32){
            auto data = _mm256_loadu_si256((const __m256i *)ptr);
            auto cmp_result = _mm256_cmpgt_epi8(zero_vec, data);
            int mask = _mm256_movemask_epi8(cmp_result);
            if (mask != 0){
                size_t offset = __builtin_ctz(mask);
                return (ptr - str) + offset;}}
        return 0;}

    size_t parse_str4_to_f64(const char *str, size_t len, double *out){
        auto zeros = _mm_set1_epi8('0');
        auto mult_10_1 = _mm_setr_epi8(
            10, 1, 10, 1, 10, 1, 10, 1,
            10, 1, 10, 1, 10, 1, 10, 1);
        auto mult_100_1 = _mm_setr_epi16(
            100, 1, 100, 1, 100, 1, 100, 1);
        auto str_end = str + len;
        for (auto end = str_end - 15; str < end; str += 16, out += 4){
            auto chars = _mm_loadu_si128((const __m128i *)str);
            auto digits = _mm_sub_epi8(chars, zeros);
            auto vals_16 = _mm_maddubs_epi16(digits, mult_10_1);
            auto vals_32 = _mm_madd_epi16(vals_16, mult_100_1);
            auto vals_double = _mm256_cvtepi32_pd(vals_32);
            _mm256_store_pd(out, vals_double);}
        for (auto end = str_end - 3; str < end; str += 4, out++){
            out[0] = str[0] * 1000 + str[1] * 100 + str[2] * 10 + str[3] - '0' * 1111;}
        size_t offset = 0,factor = 1000;
        if (str < str_end){
            offset = 4 - (str_end - str);
            out[0] = 0;
            while (str < str_end){
                out[0] += (str[0] - '0')*factor;
                str++;
                factor /= 10;
            }}
        return offset;}
    template <typename T>
    size_t conv_to_str_base10000(const T *ary, size_t conv_len, size_t shift, char *res, size_t &res_len){
        constexpr size_t BLOCK = 4;
        constexpr uint64_t BASE = 10000, BASE2 = BASE * BASE;
        res_len = (conv_len + 1) * BLOCK;
        auto end = res + res_len;
        char *p = end;
        uint64_t carry = 0;
        const size_t pairs = conv_len / 2;
        if (conv_len % 2 != 0){
            p -= BLOCK;
            carry += (uint64_t)ary[conv_len - 1];
            itosbase10000.tostr(p, carry % BASE);
            carry /= BASE;}
        for (size_t g = pairs; g > 0; g--){
            uint64_t C = (uint64_t)ary[2 * g - 2] * BASE + (uint64_t)ary[2 * g - 1];
            uint64_t total = C + carry;
            uint64_t t4 = total / BASE;
            carry = total / BASE2;
            uint32_t lo = (uint32_t)(total - t4 * BASE);
            uint32_t hi = (uint32_t)t4 - (uint32_t)carry * (uint32_t)BASE;
            p -= 2 * BLOCK;
            *(uint32_t *)p = itosbase10000.tostr(hi);
            *(uint32_t *)(p + BLOCK) = itosbase10000.tostr(lo);}
        p -= BLOCK;
        itosbase10000.tostr(p, carry);
        while (p < end && *p == '0'){
            p++;}
        if (p == end){
            p--;
            *p = '0';}
        size_t offset = p - res;
        res_len -= (offset + shift);
        return offset;}
    constexpr size_t N = size_t(1) << 19;
    static AlignMem<Float64> ary1(N), ary2(N);
    char *big_mul(const char *str1, size_t len1, const char *str2, size_t len2, char *res, size_t &res_len){
        constexpr size_t BLOCK = 4, BASE = 10000;
        size_t block_len1 = (len1 + BLOCK - 1) / BLOCK, block_len2 = (len2 + BLOCK - 1) / BLOCK;
        size_t conv_len = block_len1 + block_len2 - 1, fft_len = hint::int_ceil2(conv_len);
        fft_len = std::max<size_t>(fft_len, 256);
        size_t shift = parse_str4_to_f64(str1, len1, &ary1[0]);
        shift += parse_str4_to_f64(str2, len2, &ary2[0]);
        fill_zero(ary1.begin() + block_len1, ary1.begin() + N / 2);
        fill_zero(ary2.begin() + block_len2, ary2.begin() + N / 2);
        real_conv_avx<true>(ary1.begin(), ary2.begin(), fft_len);
        return res + conv_to_str_base10000((uint64_t *)ary1.begin(), conv_len, shift, res, res_len);
    }
    size_t preserve_strlen(size_t len1, size_t len2){
        constexpr size_t BLOCK = 4;
        size_t block_len1 = (len1 + BLOCK - 1) / BLOCK, block_len2 = (len2 + BLOCK - 1) / BLOCK;
        return (block_len1 + block_len2) * BLOCK;}
    void mul(){
        constexpr size_t STR_LEN = 2000008;
        auto str = reinterpret_cast<char *>(&ary2[ary2.size() / 2]);
        fread(str, 1, STR_LEN, stdin);
        char *s1 = str, *s2;
        size_t len1 = digitlen_avx2(str);
        s2 = s1 + len1;
        while (*s2 < '0'){
            s2++;}
        size_t len2 = digitlen_avx2(s2);
        size_t res_len = preserve_strlen(len1, len2);
        auto begin = big_mul(s1, len1, s2, len2, str, res_len);
        auto end = begin + res_len;
        if (res_len == 0){
            puts("0");}
        auto buf = reinterpret_cast<char *>(ary1.begin());
        fwrite(begin, 1, res_len, stdout);
    }}
int main(){string_util::mul();}

CompilationN/AN/ACompile OKScore: N/A

Testcase #16.259 ms9 MB + 964 KBAcceptedScore: 100


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