轮廓线dp (插头dp)

 1 #pragma comment(linker, "/STACK:102400000,102400000")
 2 
 3 #include <cstdio>
 4 #include <cstdlib>
 5 #include <cstring>
 6 #include <cmath>
 7 #include <ctime>
 8 #include <iostream>
 9 #include <algorithm>
10 #include <queue>
11 #include <map>
12 #include <set>
13 #include <vector>
14 #include <list>
15 #include <stack>
16 #include <string>
17 
18 using namespace std;
19 
20 #define PI acos(-1.0)
21 #define INF 0x3f3f3f3f
22 #define inf 0x3f
23 #define rst(a, b) memset(a, b, sizeof(a))
24 #define mod 1000000007
25 #define eps 1e-6
26 #define ok puts("ok");
27 
28 typedef long long ll;
29 typedef unsigned long long ull;
30 typedef pair<int, int> pii;
31 
32 const int maxn = 200005;
33 const int maxm = 10005;
34 
35 int dp[2][16];
36 int n, m = 4, cur;
37 
38 void update(int a, int b) {
39     if(b & (1<<m)) dp[cur][b^(1<<m)] += dp[1-cur][a];
40 }
41 
42 void solve() {
43     int cases;
44     scanf("%d", &cases);
45     for(int idx = 1; idx <= cases; idx++) {
46         scanf("%d", &n);
47         cur = 0;
48         rst(dp, 0);
49         dp[0][(1<<m)-1] = 1;
50         for(int i = 0; i < n; i++) {
51             for(int j = 0; j < m; j++) {
52                 cur ^= 1;
53                 rst(dp[cur], 0);
54                 for(int k = 0; k < (1<<m); k++) {
55                     update(k, k<<1);
56                     if(i && !(k&(1<<(m-1)))) update(k, (k<<1)^(1<<m)^1);
57                     if(j && !(k&1)) update(k, (k<<1)^3);
58                 }
59             }
60         }
61         printf("%d %d\n", idx, dp[cur][(1<<m)-1]);
62     }
63 }
64 
65 int main() {
66     solve();
67     return 0;
68 }