HDU 3278 puzzle

Hdu_3278

Although there will be a lot of States if you consider three colors, if you decide which color we want to move to the middle, the remaining two colors can be regarded as one color, therefore, you can record the result from the BFS first, read a graph, and enumerate the three colors as the color to move to the middle, and then query the steps in O (1.

# Include <stdio. h> # Include < String . H> # Include <Algorithm> # Include <Queue> # Define Hash 1000007 # Define Maxd 1000010 # Define INF 0x3f3f3f Struct Point {  Int  St, D; point () {} Point (  Int _ St, Int  _ D): ST (_ st), D (_ d ){}};  Struct  Hashmap {  Int  Head [hash], size, next [maxd], St [maxd], d [maxd];  Void  Init () {memset (Head, - 1 , Sizeof (Head), size =0  ;}  Int Find ( Int  State ){  Int I, H = State % Hash;  For (I = head [H]; I! =- 1 ; I = Next [I])  If (St [I] = State) Return  I;  Return -1  ;}  Void Push ( Int State, Int  Dis ){  Int I, H = State % Hash; ST [size] = State, d [size] = DIS; next [size] = Head [H], head [H] = size ++ ;}} HM;  Char B [ 5 ] [ 10 ];  Int ANS, code [ 5 ] [ 10  ];  Void  Init (){  Int  I, J;  For (I = 0 ; I < 4 ; I ++) scanf ( "  % S  "  , B [I]);} Int  Encode (){  Int I, j, ANS = 0  ;  For (I = 0 ; I < 4 ; I ++ )  For (J = 0 ; J < 6 ; J ++) ans = ans < 1 | Code [I] [J]; Return  Ans ;}  Void Decode ( Int  St ){  Int  I, J;  For (I = 3 ; I> = 0 ; I -- )  For (J = 5 ; J> = 0 ; J --) Code [I] [J] = sT &1 , St> = 1  ;}  Void SHR ( Int R, Int  K ){  Int  I;  If (K = 0 ) For (I = 0 ; I < 5 ; I ++) STD: swap (code [r] [I], code [r] [I +1  ]);  Else   For (I = 5 ; I> = 1 ; I --) STD: swap (code [r] [I], code [r] [I- 1  ]);}  Void SHC ( Int C, Int  K ){  Int  I;  If (K =0 ) For (I = 0 ; I < 3 ; I ++) STD: swap (code [I] [c], code [I + 1  ] [C]);  Else   For (I = 3 ; I> = 1 ; I --) STD: swap (code [I] [c], code [I- 1  ] [C]);}  Void  Prepare (){ Int  I, j, C; STD: queue <Point> Q; hm. INIT (); memset (code,  0 , Sizeof  (CODE ));  For (I = 1 ; I <= 2 ; I ++ )  For (J = 1 ; J <= 4 ; J ++) Code [I] [J] =1  ; C = Encode (); q. Push (point (c,  0 ), Hm. Push (C, 0  );  While (! Q. Empty () {point P = Q. Front (); q. Pop (); decode (P. St );  For (I = 0 ; I < 4 ; I ++ ) For (J = 0 ; J < 2 ; J ++ ) {SHR (I, j), c = Encode ();  If (Hm. Find (c) =- 1 ) Q. Push (point (C, p. D + 1 ), Hm. Push (C, p. D + 1  ); SHR (I, j ^ 1  );}  For (I = 0 ; I < 6 ; I ++ )  For (J = 0 ; J < 2 ; J ++ ) {SHC (I, j), c = Encode ();  If (Hm. Find (c) =- 1 ) Q. Push (point (C, p. D + 1 ), Hm. Push (C, p. D + 1 ); SHC (I, j ^ 1  );}}}  Void Deal ( Char  Ch ){  Int  I, j, C;  For (I = 0 ; I < 4 ; I ++ )  For (J = 0 ; J <6 ; J ++) Code [I] [J] = B [I] [J] = Ch; c = Encode (); I = Hm. Find (c); ans = STD: min (ANS, hm. d [I]);}  Void  Solve (){  Int  I, J; ans = INF; Deal (  '  B  ' ), Deal ( ' W  ' ), Deal ( '  G  '  ); Printf (  "  % D \ n  "  , ANS );}  Int  Main (){  Int  T, TT; prepare (); scanf (  "  % D  " ,&T );  For (Tt = 1 ; TT <= T; TT ++ ) {Init (); printf (  "  Case % d:  "  , TT); solve ();}  Return   0  ;}