数独解决方案检查器

Question

我在 Java 中有一个程序可以检查数独是否有效，我有两种方法，第一种是检查所有列、子网格、行的总和并判断是否为 45 ，第二个是检查所有数独的总和是否为 405，如果是，那么数独是有效的所以我正在寻找一个反例，在输入中我有一个有效的数独但程序告诉它不是有效，所以这是代码：

public class test_checker {
    static final boolean valide=true;
    static final boolean non_valide=false;

    // verify every sub-grid if it is valid
        static boolean check_subgrid(int a[][],int ei,int ej){
            int sum=0;
            for(int i=ei;i<ei+3;i++){           
                for(int j=ej;j<ej+3;j++){
                    sum=sum+a[j][i];
                }
            }
            if(sum!=45) return non_valide;
            else return valide;
        }
        //verify a sudoku by sum of every row & column & sub-grid
        static boolean Checker1(int a[][]){
            int sum=0;
            //check row
            for(int i=0;i<9;i++){
                sum=0;
                for(int j=0;j<9;j++){
                    sum=sum+a[i][j];
                }
                if(sum!=45) return non_valide;

            }
            //check column
            for(int i=0;i<9;i++){
                sum=0;
                for(int j=0;j<9;j++){
                    sum=sum+a[j][i];
                }
                if(sum!=45) return non_valide;
            }       
            //check sub-grid
            for(int i=0;i<9;i=i+3){
                for(int j=0;j<3;j=j+3){
                    if(check_subgrid(a,i,j)==non_valide) return non_valide;
                }
            }
            return valide;
        }
        //verify by sum of all sudoku  
        static boolean Checker2(int a[][]){
            int sum=0;
            for(int i=0;i<9;i++){           
                for(int j=0;j<9;j++){
                    sum=sum+a[i][j];
                }
            }   
            if(sum!=405) return non_valide;
            else return valide;
        }


    public static void main(String[] args) {
        int [][] sudoku =
            {
                {1,2,3,4,5,6,7,8,9},
                {4,5,6,7,8,9,1,2,3},
                {7,8,9,1,2,3,4,5,6},
                {3,1,2,9,7,8,6,4,5},
                {6,4,5,3,1,2,9,7,8},
                {9,7,8,6,4,5,3,1,2},
                {2,3,1,5,6,4,8,9,7},
                {5,6,4,8,9,7,2,3,1},
                {8,9,7,2,3,1,5,6,4}
            };
        if(Checker1(sudoku)) System.out.println("it's valide (checker1)!");
        else System.out.println("it's not valide !");
        if(Checker2(sudoku)) System.out.println("it's valide (checker2) !");
        else System.out.println("it's not valide !");

    }

}

Answer 1

正如@John Bollinger 所说

you should be asking is whether there is an invalid 9 by 9 grid that nevertheless does satisfy your criteria.

我想到的最简单的两种情况是：

{5,5,5,5,5,5,5,5,5},
{5,5,5,5,5,5,5,5,5},
{5,5,5,5,5,5,5,5,5},
{5,5,5,5,5,5,5,5,5},
{5,5,5,5,5,5,5,5,5},
{5,5,5,5,5,5,5,5,5},
{5,5,5,5,5,5,5,5,5},
{5,5,5,5,5,5,5,5,5},
{5,5,5,5,5,5,5,5,5}

和你的例子，你会把 0 而不是 1 和 10 而不是 9。确保每个字段在行、列和子网格中都是不同的，并且间隔为 [1,9]。

Answer 2

对于 checker2，您可以只反转两行的两个值。这里我把第一行和第二行的4和1倒过来，显然是无效的数独，但是checker2会给你一个正数

            {4,2,3,4,5,6,7,8,9},
            {1,5,6,7,8,9,1,2,3},
            {7,8,9,1,2,3,4,5,6},
            {3,1,2,9,7,8,6,4,5},
            {6,4,5,3,1,2,9,7,8},
            {9,7,8,6,4,5,3,1,2},
            {2,3,1,5,6,4,8,9,7},
            {5,6,4,8,9,7,2,3,1},
            {8,9,7,2,3,1,5,6,4}

数独解决方案检查器

Sudoku solution checker

java

artificial-intelligence

sudoku