[原创]POJ 3254 Corn Fields [状压DP]【动态规划】

2016-08-03 13:38:04 Tabris_ 阅读数：219

https://blog.csdn.net/qq_33184171/article/details/52102801

---------------------------------------------------.

Corn Fields
Time Limit: 2000MS Memory Limit: 65536K
Total Submissions: 12927 Accepted: 6766
Description

Farmer John has purchased a lush new rectangular pasture composed of M by N (1 ≤ M ≤ 12; 1 ≤ N ≤ 12) square parcels. He wants to grow some yummy corn for the cows on a number of squares. Regrettably, some of the squares are infertile and can’t be planted. Canny FJ knows that the cows dislike eating close to each other, so when choosing which squares to plant, he avoids choosing squares that are adjacent; no two chosen squares share an edge. He has not yet made the final choice as to which squares to plant.

Being a very open-minded man, Farmer John wants to consider all possible options for how to choose the squares for planting. He is so open-minded that he considers choosing no squares as a valid option! Please help Farmer John determine the number of ways he can choose the squares to plant.

Input

Line 1: Two space-separated integers: M and N
Lines 2…M+1: Line i+1 describes row i of the pasture with N space-separated integers indicating whether a square is fertile (1 for fertile, 0 for infertile)
Output

Line 1: One integer: the number of ways that FJ can choose the squares modulo 100,000,000.
Sample Input

2 3
1 1 1
0 1 0
Sample Output

9
Hint

Number the squares as follows:
1 2 3
4

There are four ways to plant only on one squares (1, 2, 3, or 4), three ways to plant on two squares (13, 14, or 34), 1 way to plant on three squares (134), and one way to plant on no squares. 4+3+1+1=9.

---------------------------------------------------.

DP 的时候主要判断的就是3项
1.左右有没有挨着的 status&(status<<1)
2.是不是只在有草的地方放牛 (草地的状态&想放牛的状态)==想放牛的状态
3.判断相邻两行的状态有没有相邻的(这时候相邻就是上下相邻) 直接 上&下 就行了

------------------------------------------.