hdu5322

脑阔疼的dp:)

#include <bits/stdc++.h>
/*
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/hash_policy.hpp>
*/
using namespace std;

const double eps = 1e-10;
const double pi = 3.1415926535897932384626433832795;
const double eln = 2.718281828459045235360287471352;

#define f(i, a, b) for (int i = a; i <= b; i++)
#define scan(x) scanf("%d", &x)
#define mp make_pair
#define pb push_back
#define lowbit(x) (x&(-x))

#define fi first
#define se second
#define SZ(x) int((x).size())
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define summ(a) (accumulate(all(a), 0ll))

typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;

using ll=long long;
const int mod=998244353,g=3,gi=332748118,NR=1<<21;
int n=1e5,a[NR],fac[(int)1e5+9],inv[(int)1e5+9],rev[NR],A[NR],B[NR],lim,bit;
int powmod(int a,int b){
    int res=1;
    for(;b>0;b>>=1,a=1ll*a*a%mod)if(b&1)res=1ll*res*a%mod;
    return res;
}

void NTT(int *a,int type){
    for(int i=0;i<lim;++i)if(i<rev[i])swap(a[i],a[rev[i]]);
    for(int k=1;k<lim;k<<=1){
        int wn=powmod(type==1?g:gi,(mod-1)/(k<<1));
        for(int i=0;i<lim;i+=(k<<1)){
            int w=1;
            for(int j=0;j<k;++j,w=1ll*w*wn%mod){
                int x=a[i+j],y=1ll*w*a[i+j+k]%mod;
                a[i+j]=(x+y)%mod,a[i+j+k]=(x-y+mod)%mod;
            }
        }
    }
    if(type==1)return ;
    int invn=powmod(lim,mod-2);
    for(int i=0;i<lim;++i){
        a[i]=1ll*a[i]*invn%mod;
    }
}

void cdq(int l,int r){
    if(l==r)return ;
    int mid=(l+r)>>1;
    cdq(l,mid);
    lim=1,bit=0;
    while(lim<=(r-l+1)*2)lim<<=1,bit+=1;
    for(int i=0;i<lim;++i)rev[i]=(rev[i>>1]>>1)|((i&1)<<(bit-1));
    for(int i=0;i<lim;++i)A[i]=B[i]=0;
    for(int i=l;i<=mid;++i)A[i-l]=1ll*a[i]*inv[i]%mod;
    for(int i=1;i<=r-l;++i)B[i]=1ll*i*i%mod;
    NTT(A,1),NTT(B,1);
    for(int i=0;i<lim;++i)A[i]=1ll*A[i]*B[i]%mod;
    NTT(A,0);
    for(int i=mid+1;i<=r;++i)a[i]=(a[i]+1ll*A[i-l]*fac[i-1]%mod)%mod;
    cdq(mid+1,r);
}

int main()
{
    ios::sync_with_stdio(false);
    cin.tie(0);

    fac[0]=fac[1]=inv[0]=1;
    for(int i=2;i<=n;++i)fac[i]=1ll*fac[i-1]*i%mod;
    inv[n]=powmod(fac[n],mod-2);
    for(int i=n-1;i;--i)inv[i]=1ll*inv[i+1]*(i+1)%mod;
    a[0]=1;
    cdq(0,n);
    while(~scanf("%d",&n))printf("%d\n",a[n]);
    return 0;
}