【HDOJ】3459 Rubik 2×2×2

模拟+DFS。

 /* 3459 */
 #include <cstdio>
 #include <cstring>
 #include <cstdlib>

 #define MAXN    10
 #define MAXL    1005

 #define U0        map[0][2]
 #define U1        map[0][3]
 #define U2        map[1][3]
 #define U3        map[1][2]

 #define F0        map[2][2]
 #define F1        map[2][3]
 #define F2        map[3][3]
 #define F3        map[3][2]

 #define R0        map[2][4]
 #define R1        map[2][5]
 #define R2        map[3][5]
 #define R3        map[3][4]

 #define L0        map[2][0]
 #define L1        map[2][1]
 #define L2        map[3][1]
 #define L3        map[3][0]

 #define B0        map[2][6]
 #define B1        map[2][7]
 #define B2        map[3][7]
 #define B3        map[3][6]

 #define D0        map[4][2]
 #define D1        map[4][3]
 #define D2        map[5][3]
 #define D3        map[5][2]

 const int n = ;
 const int m = ;
 int deep;
 char map[MAXN][MAXN];
 char op[MAXL];

 bool isValid() {
     bool ret;
     ret =\
         (U0==U1 && U0==U2 && U0==U3) &&\
         (L0==L1 && L0==L2 && L0==L3) &&\
         (R0==R1 && R0==R2 && R0==R3) &&\
         (F0==F1 && F0==F2 && F0==F3) &&\
         (B0==B1 && B0==B2 && B0==B3) &&\
         (D0==D1 && D0==D2 && D0==D3) ;
     return ret;
 }

 void rotateX() {
     char ch, ch1, ch2;
     // handle right
     ch = R0;
     R0 = R1;
     R1 = R2;
     R2 = R3;
     R3 = ch;

     ch1 = F1;
     ch2 = F2;
     // up -> front
     F1 = U1;
     F2 = U2;
     // back -> up
     U1 = B3;
     U2 = B0;
     // down -> back
     B0 = D2;
     B3 = D1;
     // front -> down
     D1 = ch1;
     D2 = ch2;
 }

 void rotateY() {
     char ch, ch0, ch1;

     // handle up
     ch = U0;
     U0 = U1;
     U1 = U2;
     U2 = U3;
     U3 = ch;

     ch0 = F0;
     ch1 = F1;
     // left -> front
     F0 = L0;
     F1 = L1;
     // back -> left
     L0 = B0;
     L1 = B1;
     // right -> back
     B0 = R0;
     B1 = R1;
     // front -> right
     R0 = ch0;
     R1 = ch1;
 }

 void rotateZ() {
     char ch, ch2, ch3;

     // handle front
     ch = F0;
     F0 = F1;
     F1 = F2;
     F2 = F3;
     F3 = ch;

     ch2 = U2;
     ch3 = U3;
     // right -> up
     U3 = R0;
     U2 = R3;
     // down -> right
     R0 = D1;
     R3 = D0;
     // left -> down
     D0 = L1;
     D1 = L2;
     // up -> left
     L1 = ch2;
     L2 = ch3;
 }

 bool dfs(int d) {
     if (d == deep)
         return isValid();

     op[d] = 'X';
     rotateX();
     if (dfs(d+))
         return true;
     rotateX();
     rotateX();
     rotateX();

     op[d] = 'Y';
     rotateY();
     if (dfs(d+))
         return true;
     rotateY();
     rotateY();
     rotateY();

     op[d] = 'Z';
     rotateZ();
     if (dfs(d+))
         return true;
     rotateZ();
     rotateZ();
     rotateZ();

     return false;
 }

 int main() {
     int i, j, k;

     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     while () {
         for (i=; i<n; ++i)
             scanf("%s", map[i]);
         if (map[][] == '.')
             break;
         deep = ;
         while () {
             if (dfs())
                 break;
             ++deep;
         }
         op[deep] = '\0';
         puts(op);
     }

     return ;
 }