多项式求逆 75pts TLE 求卡常马蜂良好
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多项式求逆 75pts TLE 求卡常马蜂良好
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_xguagua_Firefly_楼主2025/1/3 20:11

rt

#include <bits/stdc++.h>
#define int long long
using namespace std;

constexpr int MOD = 998244353,PHI = 998244352,GEN = 3,IGEN = 332748118,MAXN = 4e5 + 24;
inline int qpow(int b,int p)
{
    int res = 1;
    while(p)
    {
        if(p & 1)
            res = res * b % MOD;
        b = b * b % MOD;
        p >>= 1;
    }
    return res;
}
int n,rev[MAXN];
struct Polynomial
{
    int val[MAXN],len;
    Polynomial()
    {
        memset(val,0,sizeof(val));
        len = 0;
    };
    void NTT(int len,short type)
    {
        for(int i = 0;i < len;i++)
        {
            if(i < rev[i])
                swap(val[i],val[rev[i]]);
        }
        for(int h = 2;h <= len;h <<= 1)
        {
            int idg = qpow(type == 1 ? GEN : IGEN,PHI / h);
            for(int j = 0;j < len;j += h)
            {
                int pw = 1;
                for(int k = j;k < j + (h >> 1);k++)
                {
                    int e = val[k],o = pw * val[k + (h >> 1)] % MOD;
                    val[k] = (e + o) % MOD;
                    val[k + (h >> 1)] = ((e - o) % MOD + MOD) % MOD;
                    pw = pw * idg % MOD;
                }
            }
        }
        if(type == -1)
        {
            int inv = qpow(len,MOD - 2);
            for(int i = 0;i < len;i++)
                val[i] = val[i] * inv % MOD;
        }
    }
    Polynomial& operator*=(Polynomial a)
    {
        int L = len + a.len,Len = 1;
        while(L)
        {
            L >>= 1;
            Len <<= 1;
        }
        for(int i = 1;i < Len;i++)
        {
            rev[i] = rev[i >> 1] >> 1;
            if(i & 1)
                rev[i] |= Len >> 1;
        }
        NTT(Len,1),a.NTT(Len,1);
        for(int i = 0;i < Len;i++)
            val[i] = val[i] * a.val[i] % MOD;
        NTT(Len,-1);
        fill(val + n,val + Len,0);
        return *this;
    }
    Polynomial& operator*=(int a)
    {
        for(int i = 0;i <= len;i++)
            val[i] = (val[i] * a) % MOD;
        return *this;
    }
    Polynomial operator*(Polynomial a) const
    {
        Polynomial tmp = *this;
        return (tmp *= a);
    }
    Polynomial& operator-=(const Polynomial &a)
    {
        for(int i = 0;i <= max(len,a.len);i++)
            val[i] = (val[i] - a.val[i] + MOD) % MOD;
        return *this;
    }
    Polynomial operator-(const Polynomial &a) const
    {
        Polynomial tmp = *this;
        return (tmp -= a);
    }
    Polynomial& operator+=(const Polynomial &a)
    {
        for(int i = 0;i <= max(len,a.len);i++)
            val[i] = (val[i] + a.val[i]) % MOD;
        return *this;
    }
    Polynomial operator+(const Polynomial &a) const
    {
        Polynomial tmp = *this;
        return (tmp += a);
    }
    Polynomial GetInv()
    {
        Polynomial res,tmp;
        res.len = n - 1;
        res.val[0] = qpow(val[0],MOD - 2);
        for(int pw = 2;pw <= (n << 1);pw <<= 1)
        {
            tmp = (*this) * res * res;
            res *= 2,res -= tmp;
        }
        return res;
    }
    friend ostream& operator<<(ostream& out,Polynomial a)
    {
        for(int i = 0;i <= a.len;i++)
            out << a.val[i] % MOD << " ";
        return out;
    }
};
signed main()
{
    ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
    cin >> n;
    Polynomial F;
    F.len = n - 1;
    for(int i = 0;i < n;i++)
        cin >> F.val[i];
    cout << F.GetInv();
}
2025/1/3 20:11
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