poj3254 Corn Fields

思路：

状态压缩dp。

实现：

#include <iostream>
using namespace std;
const int MOD = 100000000;
int m, n, a[13][13], dp[13][13][1 << 13];
int main()
{
    cin >> m >> n;
    for (int i = 0; i < m; i++)
    {
        for (int j = 0; j < n; j++)
        {
            cin >> a[i][j];
        }
    }
    for (int i = 0; i < 1 << n; i++)
    {
        bool flg = true;
        for (int j = 0; j < n; j++)
        {
            if (a[m - 1][j] == 0 && i >> j & 1) 
            {
                flg = false;
                break;
            }
        }
        dp[m][0][i] = flg;
    }
    for (int i = m - 1; i >= 0; i--)
    {
        for (int j = n - 1; j >= 0; j--)
        {
            for (int k = 0; k < 1 << n; k++)
            {
                int ni = i, nj = j + 1;
                if (j == n - 1) { ni = i + 1; nj = 0; }
                dp[i][j][k] += dp[ni][nj][k & ~(1 << j)];
                dp[i][j][k] %= MOD;
                bool ok = true;
                if (a[i][j] == 0) ok = false;
                if (j && k >> (j - 1) & 1) ok = false;
                if (k >> j & 1) ok = false;
                if (ok) 
                {
                    dp[i][j][k] += dp[ni][nj][k | 1 << j];
                    dp[i][j][k] %= MOD;
                }
            }
        }
    }
    cout << dp[0][0][0] << endl;
    return 0;
}