poj1185 炮兵阵地 状压dp

 1 #include <cstdio>
 2 #include <algorithm>
 3 #include <cstring>
 4 using namespace std;
 5 typedef long long LL;
 6 const int maxn = 1e6 + 10;
 7 const int INF = 0x7fffffff;
 8 const int mod = 100000000;
 9 char tu[105][12];
10 int sum[105], mp[105], dp[105][70][70], state[105];
11 int n, m;
12 int cal(int x) {
13     int ret = 0;
14     while(x) ret += (x & 1), x >>= 1;
15     return ret;
16 }
17 int main() {
18     scanf("%d%d", &n, &m);
19     for (int i = 1 ; i <= n ; i++) {
20         scanf("%s", tu[i]);
21         for (int j = 0 ; j < strlen(tu[i]) ; j++)
22             if (tu[i][j] == ‘H‘) mp[i] |= (1 << j);
23     }
24     int tot = 0;
25     for (int i = 0 ; i < (1 << m) ; i++) {
26         if (!(i & (i <<1)) && !(i & (i << 2))) state[++tot] = i, sum[tot] = cal(i);
27     }
28     for (int i = 1 ; i <= tot ; i++)
29         if (!(state[i]&mp[1])) dp[1][1][i] = sum[i];
30     for (int i = 1 ; i < n ; i++) {
31         for (int j = 1 ; j <= tot ; j++) {
32             for (int k = 1 ; k <= tot ; k++) {
33                 if (!(state[j]&state[k]) && dp[i][j][k] ) {
34                     for (int q = 1 ; q <= tot ; q++) {
35                         if (!(state[q]&state[j]) && !(state[q]&state[k]) && !(state[q]&mp[i + 1]))
36                             dp[i+1][k][q] = max(dp[i][j][k] + sum[q], dp[i+1][k][q]);
37                     }
38                 }
39             }
40         }
41     }
42     int ans = 0;
43     for (int i = 1 ; i <= tot ; i++) {
44         for (int j = 1 ; j <= tot ; j++) {
45             ans = max(ans, dp[n][i][j]);
46         }
47     }
48     printf("%d\n", ans);
49     return 0;
50 }