HDU 1426 (Sudoku)

I just saw that many people use DFS + Pruning for Sudoku .. What's wrong with my DLX...

But think about the fact that this search pruning is really a lot, but it's still faster than DLX...

# Include <stdio. h> # Include < String . H> # Include <Iostream> Using   Namespace  STD;  # Define N 300000 # Define INF 0x3fffffff Char G [ 10 ] [ 10  ]; Int Ans [ 1000  ];  Int U [ 5000 ], D [ 5000 ], R [ 5000 ], L [ 5000 ], Num [ 5000 ], H [ 1000 ], Save [ 5000 ], Save1 [ 5000  ];  Int Flag, head;  Const   Int N = 729  ;  Const   Int M = 324  ;  Int  ID;  Void  Prepare (){  For ( Int I = 0 ; I <= m; I ++) {Num [I] = 0  ; D [I] = I; U [I] = I; R [I] = I + 1  ; L [I + 1 ] = I;} R [m] = 0  ; Memset (H, - 1 , Sizeof (H )); // Record the first vertex of each row  }  Void Link ( Int TN, Int  TM) {ID ++ ; Save1 [ID] = Tn; //  Record row ++ Num [save [ID] = Tm]; //  Record Column D [ID] = D [Tm]; U [d [Tm] = ID; U [ID] = TM; d [Tm] = ID;  If (H [tn] < 0 ) H [tn] = L [ID] = R [ID] = ID;  Else  {R [ID] = R [H [tn]; L [R [H [tn] = ID; R [H [tn] = ID; L [ID] = H [tn] ;}}  Void  Build () {ID = M; Int  SUM; prepare ();  Int Tn = 0  ;  For ( Int I = 1 ; I <= 81 ; I ++ ){  For ( Int J = 1 ; J <= 9 ; J ++){ ++ TN; Link (TN, I) ;}} sum = 81  ;  ///////////////  //      For ( Int I = 1 ; I <= 9 ; I ++) //  Each row  {Tn = (I- 1 )*81  ;  For ( Int K = 1 ; K <= 9 ; K ++ ){  Int TK = tn + K;  For ( Int J = 1 ; J <= 9 ; J ++ ) {Link (TK, Sum + (I- 1 )* 9 + K); TK + = 9  ; }}} Sum + = 81  ;  /////////////////////  //      For ( Int I = 1 ; I <= 9 ; I ++ ) {Tn = (I- 1 )* 9  ;  For ( Int K = 1 ; K <= 9 ; K ++ ){  Int TK = tn + K;  For ( Int J = 1 ; J <= 9 ; J ++) {Link (TK, Sum + (I- 1 )* 9 + K); TK + = 81  ; }}} Sum + = 81  ;  ////////////////////////  /      Int Tt = 0  ;  For (Int I1 = 1 ; I1 <= 3 ; I1 ++ ){  For ( Int J1 = 1 ; J1 <= 3 ; J1 ++ ) {Tn = (I1- 1 )* 81 * 3 + 9 * 3 * (J1- 1  );  For ( Int K = 1 ; K <= 9 ; K ++ ){ ++ TT;  Int  TK;  For ( Int I = 1 ; I <= 3 ; I ++ ){  For ( Int J = 1 ; J <= 3 ; J ++ ) {TK = Tn + (I- 1 )* 81 + 9 * (J- 1 ) + K; Link (TK, Sum +TT );}}}}}}  Void Remove ( Int  S) {L [R [s] = L [s]; R [L [s] = R [s];  For ( Int I = d [s]; I! = S; I = D [I])  For ( Int J = R [I]; J! = I; j = R [J]) {u [d [J] =U [J]; d [U [J] = D [J]; num [save [J] -- ;}}  Void Resume ( Int  S) {R [L [s] = S; L [R [s] = S;  For ( Int I = U [s]; I! = S; I = U [I])  For ( Int J = L [I]; J! = I; j =L [J]) {u [d [J] = J; d [U [J] = J; num [save [J] ++ ;}}  Void DFS ( Int  S ){  If (FLAG) Return  ;  If (R [head] = Head) {flag = 1  ; For ( Int I = 0 ; I <s; I ++ ){  Int  Ti, TJ, TK;  Int Tans = save1 [ans [I]- 1  ; Ti = (TANS )/ 81 + 1  ; TJ = (TANS % 81 )/ 9 +1  ; TK = (TANS % 81 ) % 9 + 1  ;  //  Printf ("<% d>", Ti, TJ ); G [Ti] [TJ] = TK + '  0  '  ;}  Return  ;}  Int Mi =INF, Tu;  For ( Int I = R [head]; I! = Head; I = R [I])  If (Mi> Num [I]) {mi = Num [I]; TU = I;} remove (TU );  For ( Int I = d [Tu]; I! = Tu; I = D [I]) {  For ( Int J = R [I]; J! = I; j = R [J]) Remove (save [J]); ans [s] = I; DFS (S + 1  );  For ( Int J = L [I]; J! = I; j = L [J]) Resume (save [J]);} resume (TU );}  Int  Main (){  Int Fflag = 0  ;  Char TT;  While (CIN> TT ){  If (Fflag = 1  ) {Printf (  "  \ N  "  );} Fflag = 1  ; Build ();  Int Tu = 0  ; For ( Int I = 1 ; I <= 9 ; I ++ ){  For ( Int J = 1 ; J <= 9 ; J ++ ){  If (I = 1 & J = 1 ) G [I] [J] = TT;  Else  CIN > G [I] [J];  If (G [I] [J]! = '  ?  '  ){  Int Kk = G [I] [J]- '  0  ' ; Remove (save [H [Tu + Kk]);  For ( Int I1 = R [H [Tu + KK]; I1! = H [Tu + KK]; I1 = R [I1]) {remove (save [I1]) ;}} TU + = 9  ;} Flag = 0  ; DFS (  0  );  For ( Int I = 1 ; I <= 9 ; I ++ ){  For ( Int J = 1 ; J < 9 ; J ++ ) Printf (  "  % C  "  , G [I] [J]); printf (  " % C  " , G [I] [ 9  ]); Printf (  "  \ N  "  );}}  Return   0  ;}