POJ 3254 Corn Fields (状压DP入门)

http://poj.org/problem?id=3254

状压DP:

#include<iostream>
#include<cstring>
using namespace std;

int dp[13][1<<13];
int mp[13],s[1<<13];
int n,m;

int check1(int x)
{
    return x&(x<<1);
}

int check2(int x,int p)
{
    return mp[x]&p;
}

int main()
{
    cin>>n>>m;
    memset(dp,0,sizeof(dp));
    memset(mp,0,sizeof(mp));
    memset(s,0,sizeof(s));
    for (int i=1;i<=n;i++)
    {
        for (int j=1;j<=m;j++)
        {
            int x;
            cin>>x;
            if (x==0) mp[i]+=1<<(j-1);
        }
    }
    int cut=0;
    for (int i=0;i<(1<<m);i++)
    {
        if (!check1(i)) s[cut++]=i;
    }
    for (int i=1;i<=n;i++)
    {
        for (int j=0;j<cut;j++)
        {
            if (check2(i,s[j])) continue;
            if (i==1)
            {
                dp[1][j]=1;
                continue;
            }
            for (int k=0;k<cut;k++)
            {
                if (s[j]&s[k]) continue;
                dp[i][j]+=dp[i-1][k];
            }
        }
    }
    int ans=0;
    for (int i=0;i<cut;i++)
    {
        ans=(ans+dp[n][i])%100000000;
    }
    cout<<ans<<endl;
}