[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[6][12] = {
        {0, 1, 9, 15, 19, 18, 10, 4, 22, 23, 21, 20}, {4, 10, 18, 19, 15, 9, 1, 0, 20, 21, 23, 22},
        {1, 3, 7, 13, 17, 19, 21, 23, 9, 8, 14, 15}, {23, 21, 19, 17, 13, 7, 3, 1, 15, 14, 8, 9},
        {22, 23, 9, 8, 7, 6, 5, 4, 0, 1, 3, 2}, {4, 5, 6, 7, 8, 9, 23, 22, 2, 3, 1, 0},
};
int arr2[6][4] = {{0, 1, 2, 3}, {4, 5, 10, 11}, {6, 7, 12, 13}, {8, 9, 14, 15}, {16, 17, 18, 19}, {20, 21, 22, 23}};
int n, ans;
struct Node {
        int a[24];
        void inp() {
                for(int i = 0; i < 24; i++) {
                        scanf("%d", a + i);
                }
        }
};
Node doit(Node state, int arr[])
{
        Node tmp = state;
        for(int i = 0; i < 8; i++) state.a[arr[i]] = tmp.a[arr[(i + 2) % 8]];//转两格
        for(int i = 0; i < 4; i++) state.a[arr[i + 8]] = tmp.a[arr[(i + 1) % 4 + 8]];//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 = 0;
        for(int i = 0; i < 6; i ++) {
                int F = 1;
                for(int j = 1; j < 4; j++) {
                        if(state.a[arr2[i][j]] != state.a[arr2[i][j - 1]]) {
                                F = 0;
                                break;
                        }
                }
                ans += F;
        }
        return ans;
}

void dfs(int k, Node state)
{
        if(k > n) return;
        for(int i = 0; i < 6; i++) {
                Node newState = doit(state, arr[i]);
                ans = max(ans, getAns(newState));
                dfs(k + 1, newState);
        }
}
int main()
{
        //freopen("input.txt", "r", stdin);
        //freopen("output.txt", "w", stdout);
        while(cin>> n) {
                Node state;
                state.inp();
                ans = getAns(state);
                dfs(1, state);
                cout<< ans<< endl;
        }
        return 0;
}