【POJ3254】coinfield

状压dp初步。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define N 600
#define yql 1000000000
int n,m,top,a[N],v[N],dp[][N],now[N];
inline bool lineck(int x){return  (x&(x<<))?:;}
inline void init(){
    top=;int sum=<<n;
    for(int i=;i<sum;i++)if(lineck(i))v[++top]=i;
}
inline bool fit(int x,int k){return (x&now[k])?:;}
inline int jcnt(int x){
    int cnt=;
    while(x){++cnt;x&=(x-);}
    return cnt;
}
inline int read(){
    int f=,x=;char ch;
    do{ch=getchar();if(ch=='-')f=-;}while(ch<''||ch>'');
    do{x=x*+ch-'';ch=getchar();}while(ch>=''&&ch<='');
    return f*x;
}
int main(){
    while(scanf("%d%d",&m,&n)!=EOF){
        init();memset(dp,,sizeof(dp));
        for(int i=;i<=m;i++){
            now[i]=;int x;
            for(int j=;j<=n;j++){x=read();if(!x)now[i]+=(<<(n-j));}
        }
        for(int i=;i<=top;i++)if(fit(v[i],))dp[][i]=;
        for(int i=;i<=m;i++)for(int k=;k<=top;k++){
            if(!fit(v[k],i))continue;
            for(int j=;j<=top;j++){
                if(!fit(v[j],i-))continue;
                if(v[j]&v[k])continue;
                dp[i][k]=(dp[i][k]+dp[i-][j])%yql;
            }
        }
        int ans=;
        for(int i=;i<=top;i++)ans=(ans+dp[m][i])%yql;
        printf("%d\n",ans);
    }
}