Submission #1812054

---

Source Code Expand

//by yjz
#include<bits/stdc++.h>
using namespace std;
#define FF first
#define SS second
#define PB push_back
#define MP make_pair
#define bged(v) (v).begin(),(v).end()
#define foreach(it,s) for(__typeof((s).begin()) it=(s).begin();it!=(s).end();it++)
typedef long long ll;
const int Imx=2147483647;
const ll Lbig=2e18;
const int mod=924844033;
//My i/o stream
struct fastio
{
	char s[100000];
	int it,len;
	fastio(){it=len=0;}
	inline char get()
	{
		if(it<len)return s[it++];it=0;
		len=fread(s,1,100000,stdin);
		if(len==0)return EOF;else return s[it++];
	}
	bool notend()
	{
		char c=get();
		while(c==' '||c=='\n')c=get();
		if(it>0)it--;
		return c!=EOF;
	}
}_buff;
#define geti(x) x=getnum()
#define getii(x,y) geti(x),geti(y)
#define getiii(x,y,z) getii(x,y),geti(z)
#define puti(x) putnum(x),putchar(' ')
#define putii(x,y) puti(x),puti(y)
#define putiii(x,y,z) putii(x,y),puti(z)
#define putsi(x) putnum(x),putchar('\n')
#define putsii(x,y) puti(x),putsi(y)
#define putsiii(x,y,z) putii(x,y),putsi(z)
inline ll getnum()
{
	ll r=0;bool ng=0;char c;c=_buff.get();
	while(c!='-'&&(c<'0'||c>'9'))c=_buff.get();
	if(c=='-')ng=1,c=_buff.get();
	while(c>='0'&&c<='9')r=r*10+c-'0',c=_buff.get();
	return ng?-r:r;
}
template<class T> inline void putnum(T x)
{
	if(x<0)putchar('-'),x=-x;
	register short a[20]={},sz=0;
	while(x)a[sz++]=x%10,x/=10;
	if(sz==0)putchar('0');
	for(int i=sz-1;i>=0;i--)putchar('0'+a[i]);
}
inline char getreal(){char c=_buff.get();while(c<=32)c=_buff.get();return c;}
int n,k;
ll fac[2011];
bool pre[2011],nxt[2011];
ll dp0[2011],dp1[2011],ans[2011];
int anssz;
//dp0=dp0'(1+x)+dp1'
//dp1=(dp0'+dp1')x
ll mul_a[2011];
int mul(ll a[],int na,ll b[],int nb,ll c[])
{
	for(int i=0;i<=na+nb;i++)mul_a[i]=0;
	for(int i=0;i<=na;i++)
	{
		for(int j=0;j<=nb;j++)
		{
			mul_a[i+j]=(mul_a[i+j]+a[i]*b[j])%mod;
		}
	}
	for(int i=0;i<=na+nb;i++)c[i]=mul_a[i];
	return na+nb;
}
ll ndp0[2011],ndp1[2011];
void solve(int tn)
{
	memset(dp0,0,sizeof(dp0));
	memset(dp1,0,sizeof(dp1));
	dp0[0]=1;
	for(int i=1;i<=tn;i++)
	{
		memset(ndp0,0,sizeof(ndp0));
		memset(ndp1,0,sizeof(ndp1));
		for(int j=0;j<=i;j++)ndp0[j]=(dp0[j]+dp1[j])%mod;
		if(pre[i])for(int j=1;j<=i;j++)ndp0[j]=(ndp0[j]+dp0[j-1])%mod;
		if(nxt[i])for(int j=1;j<=i;j++)ndp1[j]=(dp0[j-1]+dp1[j-1])%mod;
		swap(dp0,ndp0);
		swap(dp1,ndp1);
	}
	for(int i=0;i<=tn;i++)dp0[i]=(dp0[i]+dp1[i])%mod;
	anssz=mul(dp0,tn,ans,anssz,ans);
}
int main()
{
	fac[0]=1;
	for(int i=1;i<=2005;i++)fac[i]=fac[i-1]*i%mod;
	cin>>n>>k;
	ans[0]=1;
	for(int i=1;i<=min(n,2*k);i++)
	{
		int tn=0;
		for(int j=i;j<=n;j+=2*k)
		{
			pre[++tn]=j-k>=1;
			nxt[tn]=j+k<=n;
		}
		solve(tn);
	}
	ll res=0;
	for(int i=0;i<=n;i++)
	{
		ll cur=ans[i]*fac[n-i]%mod;
		if(i&1)res-=cur;
		else res+=cur;
	}
	res=(res%mod+mod)%mod;
	cout<<res<<endl;
	return 0;
}

Submission Info

Judge Result