Cod sursa(job #998021)

Utilizator dariusdariusMarian Darius dariusdarius Data 15 septembrie 2013 15:24:57
Problema Cowfood Scor 48
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.56 kb
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
const int mod=3210121;
unsigned short f[20][31];
int pw(int x,int y)
{
	int r;
	for(r=1;y;y>>=1)
	{
		if(y&1) r=(1LL*r*x)%mod;
		x=(1LL*x*x)%mod;
	}
	return r;
}
int invmod(int x) {return pw(x,mod-2);}
int fact[10005];
int C(int n,int k)
{
	int ans=fact[n];
	ans=(1LL*ans*invmod(fact[k]))%mod;
	ans=(1LL*ans*invmod(fact[n-k]))%mod;
	return ans;
}
int d[10005];
unsigned short list[1<<20][30];
short int ind[1<<20];
int main()
{
	freopen("cowfood.in","r",stdin);
	freopen("cowfood.out","w",stdout);
	int k,s,n;
	scanf("%d%d%d",&k,&s,&n);
	for(int i=0;i<n;i++)
		for(int j=0;j<k;j++)
			scanf("%hu",&f[i][j]);
	fact[0]=1;
	for(int i=1;i<=s+k-1;i++)
		fact[i]=(1LL*fact[i-1]*i)%mod;
	d[0]=1;
	for(int i=1;i<=s;i++)
		d[i]=(C(i+k-1,k-1)+d[i-1])%mod;
	for(int i=0;i<20;i++)
		ind[1<<i]=i;
	int ans=0;//C(s+n-1,n-1);fprintf(stderr,"%d\n",ans);
	for(int i=0;i<(1<<n);i++)
	{
		if(i!=0)
			memcpy(list[i],list[i&(i-1)],sizeof(list[i]));
		int ind,S=s,semn=1;
		for(int I=i;I;I&=(I-1)) semn=-semn;
		ind=(::ind)[i^(i&(i-1))];
		for(int j=0;j<k;j++)
			if(list[i][j]<f[ind][j])
				list[i][j]=f[ind][j];
		if(i==0) memset(list[i],0,sizeof(list[i]));
		for(int j=0;j<k;j++)
			S-=list[i][j];
		//fprintf(stderr,"%d -> %d, %d",i,semn[i],ans);
		//fprintf(stderr,"%d, %d->",i,ind);
		//for(int j=1;j<=k;j++)
		//	fprintf(stderr,"%d ",list[i][j]);
		//fprintf(stderr,"\n");
		ans=ans+semn*d[S];
		if(ans<0)    ans+=mod;
		if(ans>=mod) ans-=mod;
		//fprintf(stderr,"->%d\n",ans);
	}
	printf("%d\n",(ans-s*k-1+mod)%mod);
	return 0;
}