Java Sudoku Solution Verifier

问题

I am currently attempting to create a Java program that reads 81 integers (1-9) into an 9 X 9 matrix, and then tests to see if that matrix is a solution to a Sudoku puzzle. The parameters for a Sudoku solution are as follows: each number (1-9) must be represented in every row, column, and 3x3 square without any repetition in these areas. I have written a method to verify that the parameters are met for all rows and columns, however, I am struggling with coming up with an algorithm to verify the squares. Here is what I have so far:

import java.util.*;
public class SudokuCheck
{
  public static boolean sudokuCheck(int[][] s)
  {
    for(int row=0;row<9;row++)
      for(int col=0;col<8;col++)
      if(s[row][col]==s[row][col+1]){
      return false;}
     //Verifies rows

    for(int col2=0;col2<9;col2++)
      for(int row2=0;row2<8;row2++)
      if (s[row2][col2]==s[row2+1][col2])
      return false;
    //verifies columns

    return true;    
  }


  public static void main (String[] args)
  {
    Scanner input = new Scanner(System.in);

    int[][] solution = new int [9][9];
    System.out.println("Enter the values of a 9 X 9 Sudoku solution");

    for(int i=0;i<9;i++)
      for(int j=0;j<9;j++)
      solution[i][j]=input.nextInt();
    //read values into matrix


    if(sudokuCheck(solution)==true)
      System.out.println("The entered 9 X 9 grid is a solution to a Sudoku puzzle.");
else
  System.out.println("The entered 9 X 9 grid is not a solution to a Sudoku puzzle.");
  }
}

回答1:

This can probably be optimized but following your approach

// row checker
for(int row = 0; row < 9; row++)
   for(int col = 0; col < 8; col++)
      for(int col2 = col + 1; col2 < 9; col2++)
         if(s[row][col]==s[row][col2])
            return false;

// column checker
for(int col = 0; col < 9; col++)
   for(int row = 0; row < 8; row++)
      for(int row2 = row + 1; row2 < 9; row2++)
         if(s[row][col]==s[row2][col])
            return false;

// grid checker
for(int row = 0; row < 9; row += 3)
   for(int col = 0; col < 9; col += 3)
      // row, col is start of the 3 by 3 grid
      for(int pos = 0; pos < 8; pos++)
         for(int pos2 = pos + 1; pos2 < 9; pos2++)
            if(s[row + pos%3][col + pos/3]==s[row + pos2%3][col + pos2/3])
               return false;

回答2:

I hope it helps you

public static void main(String[] args) throws Exception {
    int[][] f = {{4,2,9,8,1,3,5,6,7}, {5,1,6,4,7,2,9,3,8}, {7,8,3,6,5,9,2,4,1},
                 {6,7,2,1,3,4,8,5,9}, {3,9,5,2,8,6,1,7,4}, {8,4,1,7,9,5,6,2,3}, 
                 {1,5,8,3,6,7,4,9,2}, {9,3,4,5,2,8,7,1,6}, {2,6,7,9,4,1,3,8,5}};
    System.out.println(Arrays.toString(f));
    System.out.println(checkBlock(f, 2, 2));
}

public static boolean checkBlock(int[][] f, int z, int s) throws Exception {
    boolean[] mark = new boolean[9];
    boolean res = true;
    for (int i = 0; i < 3; ++i) {
        for (int j = 0; j < 3; ++j) {
            int v = f[z * 3 + i][s * 3 + j];
            if (v == 0) {
                res = false;
            }
            if (mark[v - 1]) {
                throw new Exception();
            }
            mark[v - 1] = true;
        }
    }
    return res;
}

回答3:

public class SudokuVerify {
    public static void main(String[] args) {
        int[][] arr = { { 5, 3, 4, 6, 7, 8, 9, 1, 2 },
                { 6, 7, 2, 1, 9, 5, 3, 4, 8 }, { 1, 9, 8, 3, 4, 2, 5, 6, 7 },
                { 8, 5, 9, 7, 6, 1, 4, 2, 3 }, { 4, 2, 6, 8, 5, 3, 7, 9, 1 },
                { 7, 1, 3, 9, 2, 4, 8, 5, 6 }, { 9, 6, 1, 5, 3, 7, 2, 8, 4 },
                { 2, 8, 7, 4, 1, 9, 6, 3, 5 }, { 3, 4, 5, 2, 8, 6, 1, 7, 9 } };
        boolean flag = true;
        int ExpectedVal = (1 ^ 2 ^ 3 ^ 4 ^ 5 ^ 6 ^ 7 ^ 8 ^ 9);
        int ActualVal = 0;
//---># Checking for row Validation**
        for (int row = 0; row < 9; row++) {
            ActualVal = 0;
            for (int col = 0; col < 9; col++) {
                ActualVal ^= arr[row][col];
            }
            if (ActualVal != ExpectedVal) {
                flag = false;
                break;
            }
        }
//---># **Checking for col Validation**
        if (flag) {
            for (int row = 0; row < 9; row++) {
                ActualVal = 0;
                for (int col = 0; col < 9; col++) {
                    ActualVal ^= arr[col][row];
                }
                if (ActualVal != ExpectedVal) {
                    flag = false;
                    break;
                }
            }
        }
//---># **Checking for inside box Validation**
        if (flag) {
            for (int i = 0; i < 9; i += 3) {

                if (flag) {
                    for (int j = 0; j < 9; j += 3) {
                        ActualVal = 0;
                        for (int ii = i; ii < (i + 3); ii++) {
                            for (int jj = j; jj < (j + 3); jj++) {
                                ActualVal ^= arr[ii][jj];
                            }
                            System.out.println();
                        }
                        if (ActualVal != ExpectedVal) {
                            flag = false;
                            break;
                        }
                    }
                } else
                    break;

            }
        }
        if (flag)
            System.out.println("Passes");
        else {
            System.out.println("Faied");
        }
    }
}

来源：https://stackoverflow.com/questions/34076389/java-sudoku-solution-verifier