思路

按如下式子计算即可

\[ B(x)=\frac{A(x)+B'^2(x)}{2B'(x)} \]

代码

// luogu-judger-enable-o2#include 
    
     #include 
     
      #include 
      
       #define int long longusing namespace std;const int MAXN = 300000;const int G = 3;const int invG = 332748118;const int MOD = 998244353;int n;struct Poly{    int t;//次数界    int data[MAXN];    Poly(){}    Poly(int x,int val[]){        for(int i=0;i<=x;i++)            data[i]=val[i];    }};int pow(int a,int b){    int ans=1;    while(b){        if(b&1)            ans=(1LL*ans*a)%MOD;        a=(1LL*a*a)%MOD;        b>>=1;    }    return ans;}void rever(Poly &a){    for(int i=0,j=a.t;i
       
        >j)&1)                t|=(1<<(lim-j-1));        if(i
        
         >1,len);    static Poly tmp1,tmp2,tmp;    while((dep<<1)>len)        len<<=1;    for(int i=0;i
         
          >1); // printf("dep=%lld\n",dep); while((dep<<1)>(midlen)) midlen<<=1; static Poly tmp1,tmp2,tmp3; tmp1=b;tmp3=b; save(tmp1,dep-1); save(tmp3,dep-1); save(tmp2,-1); int midlent=1; for(int i=0;i