bzoj1725: [Usaco2006 Nov]Corn Fields牧场的安排 状压dp

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#define fo(i,a,b) for(int i=a;i<=b;i++)
#define fod(i,a,b) for(int i=a;i>=b;i--)
using namespace std;
const int N=(1<<12)+10,Mod=1000000000;
typedef long long ll;
ll f[14]
;
int n,m;
int c1[14]
,jd[14][14];
void pre()
{
for(int i=1;i<=n;i++)
for(int j=0;j<(1<<m);j++)
if((j&(j>>1))==0)
for(int k=1;k<=m;k++){
if((j&(1<<(k-1)))&&!jd[i][k])break;
if(k==m)c1[i][j]=1;
}
}
int main()
{
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++)
for(int j=1;j<=m;j++)
scanf("%d",&jd[i][j]);
pre();
for(int i=0;i<(1<<m);i++)if(c1[1][i])f[1][i]=1;
for(int i=1;i<n;i++)
for(int k=0;k<(1<<m);k++) if(c1[i+1][k])
for(int j=0;j<(1<<m);j++) if((k&j)==0)
f[i+1][k]=(f[i+1][k]+f[i][j])%Mod;
ll ans=0;
for(int i=0;i<(1<<m);i++)if(c1
[i])ans=(ans+f
[i])%Mod;
printf("%lld\n",ans);
return 0;
}