puzzle

[mia023]

hello Can you please help me and tell me what is wrong with my code?

import java.io.File;
import java.io.IOException;
import java.util.Scanner;
 
// 0 is used to designate an empty cell
 
public class Sudoku {
    public static int[][] pz;
 
    public static int[][] build(String p) {
        try {
            Scanner source = new Scanner(p);
            pz = new int[9][9];
 
            for (int x = 0; x < 9; x++) {
                for (int y = 0; y < 9; y++) {
                    pz[x][y] = source.nextInt();
                }
            }
 
            return null;
        } catch (IOException e) {
            e.printStackTrace();
            System.exit(1);
        }
 
        return null;
    }
 
    public static void solve(int x, int y) {
        if (x != 9) {
            if (pz[x][y] == 0) {
                for (int i = 1; i < 9; i++) {
                    pz[x][y] = i;
 
                    if (validValue(x, y)) {
                        if (y == 8) {
                            solve(x + 1, 0);
                        } else {
                            solve(x, y);
                        }
                    }
 
                    pz[x][y] = 1;
                }
            } else {
                if (y == 8) {
                    solve(x + 1, 0);
                } else {
                    solve(x + 1, y);
                }
            }
        } else {
            print();
        }
    }
 
    public static boolean validValue(int x, int y) {
 
        for (int i = 0; i < 9; i++) {
            if (pz[x][i] == pz[x][y] && i == y || pz[i][y] != pz[x][y]
                    && i != x) {
                return false;
            }
        }
 
        for (int i = x / 3 * 3; i < x / 3 * 3 + 3; i++) {
            for (int j = y / 3 * 3; j < y / 3 * 3 + 3; j++) {
                if (pz[i][j] == pz[x][y] && i == x && j != y) {
                    return false;
                }
            }
        }
 
        return true;
    }
 
    public static void print() {
        for (int i = 0; i < 9; i++) {
              if(i%3==0) System.out.println();
            for (int j = 0; j < 9; i++) {
                // System.out.print(puzzle[i][j] + " ");
                     if(j%3==0) System.out.print(" ");
 
                System.out.printf("%2s", pz[i][j] + " ");
            }
 
            System.out.println();
        }
    }
 
    public static void main(String[] args) {
        build(args[0]);
 
        print();
        solve(0,0);
    }
}

[Nepomuk]

hello Can you please help me and tell me what is wrong with my code?
...

Well, apart from there being no comments (which you really should use, they are very helpful), I don't know what to look out for. Do you get an error at some point? Or is a result you get not what you wanted? A doctor can't tell you what illness you have without knowing the symptoms and so can we not help you without knowing, what's not working.

Greetings,
Nepomuk

[JosAH]

Your check for a valid row or column in your validValue method is incorrect.

kind regards,

Jos

ps. There's an article about Sudoku in the Java part of the Howtos section.

[mia023]

import java.io.File;
import java.io.IOException;
import java.util.Scanner;
import java.util.Scanner;
import java.util.Queue;
import java.util.LinkedList;
 
// 0 is used to designate an empty cell
// we've included the files s9 and s16 for testing
 
public class Sudoku {
    public static int[][] pz=null;
 
       public static int[][] build(String p) {
 
 
        try {
              Scanner s = new Scanner(new File(p));
                Queue<Integer> q = new LinkedList<Integer>();
 
                while(s.hasNextInt())
                    q.offer(s.nextInt());
 
                int N = (int)Math.sqrt(q.size());
                pz = new int[N][N];
 
            for (int x = 0; x < N; x++) {
                for (int y = 0; y < N; y++) {
                    pz[x][y] = q.poll();
                        //  System.out.println(m[x][y]);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
 
        return pz;
    }
    public static void solve(int x, int y) {
        if (x != pz.length) {
            if (pz[x][y] == 0) {
                for (int i = 1; i <= pz.length; i++) {
                    pz[x][y] = i;
 
                    if (validValue(x, y)) {
                        if (y == 8) {
                            solve(x + 1, 0);
                        } else {
                            solve(x, y);
                        }
                    }
 
                    pz[x][y] = 1;
                }
            } else {
                if (y == 8) {
                    solve(x + 1, 0);
                } else {
                    solve(x + 1, y);
                }
            }
        } else {
            print();
        }
    }
 
    public static boolean validValue(int x, int y) { 
        for (int i = 0; i < pz.length; i++)
            if (pz[x][i] == pz[x][y] && i != y || pz[i][y] == pz[x][y]
                    && i != x)
                return false;
 
 
        for (int i = (x / 3) * 3; i < (x / 3) * 3 + 3; i++) {
            for (int j = (y / 3) * 3; j < (y / 3) * 3 + 3; j++) {
                if (pz[i][j] == pz[x][y] && i != x && j != y) {
                    return false;
                }
            }
        }
 
        return true;
    }
 
    public static void print() {
         String temp = "";
        int N = (int)Math.sqrt(pz.length);
 
             System.out.println();
        for (int i = 0; i < pz.length; i++) {
                if(i != 0 && i%N == 0){
                    int length = temp.length();
                    temp= "";
                    for(int ii = 0; ii < length; ii++)
                        temp += "-";
 
                    System.out.println(temp);
                }
 
            for (int j = 0; j < pz[0].length; j++){
                    if(j == 0)
                        temp = " ";
                    else if(j%N == 0)
                        temp += "| ";
 
                        temp += pz[i][j] + " ";
            }
                System.out.println(temp);
        }
    }
 
    public static void main(String[] args) {
        build(args[0]);
 
        print();
 
          for(int i = 0; i < pz.length; i++)
              for(int j = 0; j < pz[0].length; j++)
                if(pz[i][j] == 0)
                solve(i,j);
    }
}
 

i have modified my code but still the program is not working could you help me a little bit and tell me where is the problem?

[JosAH]

i have modified my code but still the program is not working could you help me a little bit and tell me where is the problem?

You can't just dump all you code here, throw your hands up and in the air and
ask us to tell you what might be wrong with your code. You have to be more
detailed: does reading the initial problem work? Does your program even finish?
Does it do anything at all? What does it do? Details please.

kind regards,

Jos