package sodoku.puzzler;

/**

* 求解Sodoku Puzzler的工具类

* @author Eastsun

*/

public class Solver{

protected static final int SIZE = Puzzler.SIZE;

//避免生成该类实例

protected Solver(){

}

public static boolean solve(Puzzler p){

int[][] num =new int[SIZE][SIZE];

boolean[][] rFlags =new boolean[SIZE][SIZE+1],

cFlags =new boolean[SIZE][SIZE+1],

zFlags =new boolean[SIZE][SIZE+1];

for(int r=0;r

for(int c=0;c

if(p.isFixed(r,c)){

int t =p.getNumber(r,c);

num[r][c] =t;

rFlags[r][t] =true;

cFlags[c][t] =true;

zFlags[r/3*3+c/3][t] =true;

}

int r =0,c =0;

outLoop:

for(;;){//

if(p.isFixed(r,c)){

c ++;

if(c>=SIZE){

c =0;

r ++;

if(r>=SIZE) break outLoop;

}

continue outLoop;

} //if(p.isFixed())

int t =SIZE;

for(c++;;){//

if(t>=SIZE){

c --;

if(c<0){

c =SIZE -1;

r --;

if(r<0) break outLoop;

}

if(p.isFixed(r,c)) continue;

t =num[r][c];

if(t!=0){

rFlags[r][t] =false;

cFlags[c][t] =false;

zFlags[r/3*3+c/3][t] =false;

num[r][c] =0;

}

} else{

t ++;

if(!(rFlags[r][t]||

cFlags[c][t]||

zFlags[r/3*3+c/3][t])

) break;

}

}//for(c++;;);

num[r][c] =t;

rFlags[r][t] =true;

cFlags[c][t] =true;

zFlags[r/3*3+c/3][t] =true;

c ++;

if(c>=SIZE){

c =0;

r ++;

if(r>=SIZE) break outLoop;

}

}

if(r<0) return false;

for(r=0;r

for(c=0;c

if(!p.isFixed(r,c)) p.setNumber(r,c,num[r][c]);

return true;

}

//test

public static void main(String[] args){

Puzzler p =new Puzzler();

int[][] data ={{0,0,0, 0,0,4, 0,7,6},

{8,0,1, 0,0,0, 0,3,0},

{0,4,6, 0,0,3, 0,0,0},

{0,0,0, 0,2,0, 7,0,1},

{1,0,0, 7,0,6, 0,0,5},

{5,0,7, 0,3,0, 0,0,0},

{0,0,0, 9,0,0, 8,1,0},

{0,5,0, 0,0,0, 2,0,4},

{9,1,0, 8,0,0, 0,0,0}

};

p.setPuzzler(data);

System.out.println(solve(p));

for(int r =0;r

for(int c=0;c

System.out.println();

}

}

}