数独算法

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;


public final class Demo {

	final static int MACH_RESULT = -1;	//多解
	final static int NONE_RESULT = 0;	//无解
	/*
	Description  
	         推理数独数字
	Input Param 
	         sdata  需要推理的数独数据
	Return Value
	         推理成功的数组
	         失败或其他异常返回null
	*/
	public static  int[][] sudokuDataSolve(int[][] sdata)
	{
		int i =0,j = 0;
		while(!isGameOver(sdata)){
			
			if(sdata[i][j] == 0){
				int num = theValue(sdata,i,j);
				if(num == NONE_RESULT){
					return null;
				}else if(num > 0){
					sdata[i][j] = num;
					i = 0;
					j = 0;
				}
			}
			j ++;
			if(j == 9){
				j = 0;
				i ++;
				if(i == 9){
					return null;
				}
			}
			
		}
		
		return sdata;
	}
	public static int theValue(int[][] sdate,int row,int line){
		List<Integer> maybeValue = new ArrayList<Integer>();
		maybeValue.add(1);
		maybeValue.add(2);
		maybeValue.add(3);
		maybeValue.add(4);
		maybeValue.add(5);
		maybeValue.add(6);
		maybeValue.add(7);
		maybeValue.add(8);
		maybeValue.add(9);
		for (int i = 0; i < 9; i++) {
			if(sdate[row][i] != 0){
				maybeValue.remove(new Integer(sdate[row][i]));
			}
			if(sdate[i][line] != 0){
				maybeValue.remove(new Integer(sdate[i][line]));
			}
		}
		for (int i = 0; i < 3; i++) {
			for (int j = 0; j < 3; j++) {
				if(sdate[row / 3 + i][line / 3 + j] != 0){
					maybeValue.remove(new Integer(sdate[row / 3 + i][line / 3 + j]));
				}
			}		
		}
		if (maybeValue.size() == 1) {
			return maybeValue.get(0);
		}else if (maybeValue.size() == 0) {
			return  NONE_RESULT;	//无解
		}else{
			return MACH_RESULT;
		}
		
	}
	public static boolean isGameOver(int[][] sdata){
		for (int i = 0; i < sdata.length; i++) {
			for (int j = 0; j < sdata[0].length; j++) {
				if(sdata[i][j] == 0){
					return false;
				}
			}
		}
		return true;
	}
	
}