[hdu4801]搜索

http://acm.hdu.edu.cn/showproblem.php?pid=4801

状态和生成状态的过程处理好了，这个题就是简单的搜索题了==

 #include <iostream>
 #include <cstdio>
 #include <cstring>
 #include <cmath>
 #include <algorithm>
 #include <map>
 #include <stack>
 #include <string>
 #include <ctime>
 #include <queue>
 #define mem0(a) memset(a, 0, sizeof(a))
 #define mem(a, b) memset(a, b, sizeof(a))
 #define lson l, m, rt << 1
 #define rson m + 1, r, rt << 1 | 1
 #define eps 0.0000001
 #define lowbit(x) ((x) & -(x))
 #define memc(a, b) memcpy(a, b, sizeof(b))
 #define x_x(a) ((a) * (a))
 #define LL long long
 #define DB double
 #define pi 3.14159265359
 #define MD 10000007
 #define INF (int)1e9
 #define max(a, b) ((a) > (b)? (a) : (b))
 using namespace std;
 int arr[][] = {
         {, , , , , , , , , , , }, {, , , , , , , , , , , },
         {, , , , , , , , , , , }, {, , , , , , , , , , , },
         {, , , , , , , , , , , }, {, , , , , , , , , , , },
 };
 int arr2[][] = {{, , , }, {, , , }, {, , , }, {, , , }, {, , , }, {, , , }};
 int n, ans;
 struct Node {
         int a[];
         void inp() {
                 for(int i = ; i < ; i++) {
                         scanf("%d", a + i);
                 }
         }
 };
 Node doit(Node state, int arr[])
 {
         Node tmp = state;
         for(int i = ; i < ; i++) state.a[arr[i]] = tmp.a[arr[(i + ) % ]];//转两格
         for(int i = ; i < ; i++) state.a[arr[i + ]] = tmp.a[arr[(i + ) %  + ]];//转一格，这里想都没想写成了走两格，wa了无数次，写搜    索题一定要细心啊
         return state;
 }
 int getAns(Node state)
 {
         int ans = ;
         for(int i = ; i < ; i ++) {
                 int F = ;
                 for(int j = ; j < ; j++) {
                         if(state.a[arr2[i][j]] != state.a[arr2[i][j - ]]) {
                                 F = ;
                                 break;
                         }
                 }
                 ans += F;
         }
         return ans;
 }

 void dfs(int k, Node state)
 {
         if(k > n) return;
         for(int i = ; i < ; i++) {
                 Node newState = doit(state, arr[i]);
                 ans = max(ans, getAns(newState));
                 dfs(k + , newState);
         }
 }
 int main()
 {
         //freopen("input.txt", "r", stdin);
         //freopen("output.txt", "w", stdout);
         while(cin>> n) {
                 Node state;
                 state.inp();
                 ans = getAns(state);
                 dfs(, state);
                 cout<< ans<< endl;
         }
         return ;
 }