package sudoku;

import java.lang.Enum.*;
import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;

import javax.swing.JTextField;

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ListView;
import javafx.scene.control.TextField;
import javafx.scene.layout.*;
import javafx.scene.text.TextAlignment;
import javafx.stage.Stage;

public class SudokuMain extends Application {

	@Override
	public void start(Stage primaryStage) throws Exception {
		BorderPane root = new BorderPane();

		Scene scene = new Scene(root, 500, 525);

		primaryStage.setTitle("Sudoku");
		primaryStage.setScene(scene);

		ObservableList<Sudoku> obsSud = FXCollections.observableArrayList(new Sudoku());

		TilePane tp = new TilePane();
		tp.setPrefColumns(9);
		tp.setMaxWidth(500);
		tp.setMaxHeight(500);

		tp.setHgap(5);
		tp.setVgap(5);
		HashMap<String, Integer> check = new HashMap<String, Integer>();

		for (int i = 1; i < 10; i++) {
			String iVal = ((Integer) i).toString();
			check.put(iVal, i);
		}
		for (int i = 0; i < 81; i++) {

			TextField tf = new TextField();
			tf.setMaxWidth(50);
			tf.setPrefHeight(50);
			tf.setAlignment(Pos.CENTER);

			tp.getChildren().add(tf);

			int row = (i - i % 9) / 9;
			int col = i % 9;
			int regR = (int) Math.floor(row / 3);
			int regC = (int) Math.floor(col / 3);
			int sum = regR + regC;

			if (sum % 2 == 0) {
				((TextField) tp.getChildren().get(i))
						.setStyle("-fx-background-radius:0; -fx-background-color:#9CD777;");
			} else {
				((TextField) tp.getChildren().get(i))
						.setStyle("-fx-background-radius:0; -fx-background-color:#FFFFFF;");
			}
		}

		root.setCenter(tp);

		HBox hbox = new HBox();
		TextField txtF = new TextField();
		Button solve = new Button("Solve");
		Button clear = new Button("Clear");

		clear.setOnAction((event) -> {
				txtF.setText("");
			for (int i = 0; i < 81; i++) {
				((TextField) tp.getChildren().get(i)).setText("");
				int row = (i - i % 9) / 9;
				int col = i % 9;
				int regR = (int) Math.floor(row / 3);
				int regC = (int) Math.floor(col / 3);
				int sum = regR + regC;

				if (sum % 2 == 0) {
					((TextField) tp.getChildren().get(i))
							.setStyle("-fx-background-radius:0; -fx-background-color:#9CD777;");
				} else {
					((TextField) tp.getChildren().get(i))
							.setStyle("-fx-background-radius:0; -fx-background-color:#FFFFFF;");
				}
			}
		});

		solve.setOnAction((event) -> {

			for (int i = 0; i < 81; i++) {
				String valTxt = ((TextField) tp.getChildren().get(i)).getText();
				if (valTxt.isEmpty() == false) {

					int row = (i - i % 9) / 9;
					int col = i % 9;
					if (check.containsKey(valTxt)) {
						int val = check.get(valTxt);
						obsSud.get(0).setValue(row, col, val);
					} else {
						((TextField) tp.getChildren().get(i))
								.setStyle("-fx-background-radius:0; -fx-background-color:#DF5151;");
						try {
							int val = Integer.parseInt(valTxt);
							obsSud.get(0).setValue(row, col, val);
						} catch (NumberFormatException e) {
							obsSud.get(0).setValue(row, col, 10);
						}
					}
				}
			}

			if (obsSud.get(0).sudokuSolver()) {
				for (int i = 0; i < 81; i++) {
					int row = (i - i % 9) / 9;
					int col = i % 9;
					String s = ((Integer) obsSud.get(0).getValue(row, col)).toString();
					((TextField) tp.getChildren().get(i)).setText(s);
				}
				txtF.setText("Här är lösningen");
			} else {
				txtF.setText("Finns ej lösning");
			}
			obsSud.set(0, new Sudoku());

		});

		hbox.getChildren().addAll(solve, clear, txtF);
		root.setBottom(hbox);

		primaryStage.show();
	}

	public static void main(String[] args) {
		Application.launch(args);
	}
}


package sudoku;

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

public class Sudoku {
	HashMap<Integer, ArrayList<Integer>> rows;
	HashMap<Integer, ArrayList<Integer>> cols;
	HashMap<String, ArrayList<Integer>> reg;
	int[][] matrix;

	/**
	 * Creates an empty 9x9 matrix to be used as an sudoku. Instantiate the
	 * attribute HashMaps which are corresponding to the Sudokus rows, columns and
	 * regions.
	 */
	public Sudoku() {
		matrix = new int[9][9];

		rows = new HashMap<Integer, ArrayList<Integer>>();
		cols = new HashMap<Integer, ArrayList<Integer>>();
		reg = new HashMap<String, ArrayList<Integer>>();

	}

	/**
	 * Sets the value at the square specified by the paramaters, and inserts the
	 * value in the attribute HashMaps. Index: 0 -> 8.
	 * 
	 * @param row  corresponding to the row where the value is to be set.
	 * @param col  corresponding to the column where the value is to be set.
	 * @param val, the value to be inserted.
	 */
	public void setValue(int row, int col, int val) {

		matrix[row][col] = val;
		int regR = (int) Math.floor(row / 3);
		int regC = (int) Math.floor(col / 3);
		String regName = regR + ", " + regC;

		if (rows.containsKey(row)) {
			rows.get(row).add(val);
		} else {
			rows.put(row, new ArrayList<Integer>());
			rows.get(row).add(val);
		}

		if (cols.containsKey(col)) {
			cols.get(col).add(val);
		} else {
			cols.put(col, new ArrayList<Integer>());
			cols.get(col).add(val);
		}

		if (reg.containsKey(regName)) {
			reg.get(regName).add(val);
		} else {
			reg.put(regName, new ArrayList<Integer>());
			reg.get(regName).add(val);
		}
	}

	/**
	 * Removes an existing value at the specified square, and removes the value from
	 * the attribute HashMaps. Index: 0 -> 8.
	 * 
	 * @param row corresponding to the row where the value is to be removed.
	 * @param col corresponding to the column where the value is to be removed.
	 */

	public void removeValue(int row, int col) {
		Integer val = matrix[row][col];
		int regR = (int) Math.floor(row / 3);
		int regC = (int) Math.floor(col / 3);
		String regName = regR + ", " + regC;

		matrix[row][col] = 0;
		rows.get(row).remove(val);
		cols.get(col).remove(val);
		reg.get(regName).remove(val);
	}

	/**
	 * Checks if the values in the HashMaps is an integer between 1-9, also checks
	 * if there exists no duplicate values in these HashMaps.
	 * 
	 * @return true if all checks pass, otherwise false.
	 */
	private boolean check() {
		Set<Integer> set = new HashSet<Integer>();
		for (int i = 1; i < 10; i++) {
			set.add(i);
		}

		for (Integer row : rows.keySet()) {
			Set<Integer> rowSet = new HashSet<Integer>(rows.get(row));
			if (rowSet.size() != rows.get(row).size() || !set.containsAll(rows.get(row))) {
				return false;
			}
			for (Integer col : cols.keySet()) {
				Set<Integer> colSet = new HashSet<Integer>(cols.get(col));
				if (colSet.size() != cols.get(col).size()) {
					return false;
				}
				int regR = (int) Math.floor(row / 3);
				int regC = (int) Math.floor(col / 3);
				String regName = regR + ", " + regC;
				Set<Integer> regSet = new HashSet<Integer>(reg.get(regName));
				if (regSet.size() != reg.get(regName).size()) {
					return false;
				}
			}
		}
		return true;
	}

	/** Evaluates which the next position in the Sudoku is, and returns it as an array. 
	 * If the parameter indices corresponds to the end of a row, the row increments by 1 and the column is reset to 0. 
	 * Otherwise the row value is unchanged while the column value is incremented by 1. 
	 * @param row corresponding to the position in the Sudoku, from which the next position is to be evaluated.
	 * @param col corresponding to the position in the Sudoku, from which the next position is to be evaluated.
	 * @return the next position in the Sudoku, if the position is at the end return [-1, -1].
	 */
	private int[] nextPos(int row, int col) {
		int[] pos = new int[2];
		if (col == 8 && row == 8) {
			pos[0] = -1;
			pos[1] = -1;
		} else if (col == 8 && row != 8) {
			pos[0] = row + 1;
			pos[1] = 0;
		} else {
			pos[0] = row;
			pos[1] = col + 1;
		}
		return pos;
	}

	/**
	 * Checks if the value already exists in given row/column/region.
	 * @param row corresponding to the row in the Sudoku.
	 * @param col corresponding to the column in the Sudoku.
	 * @param val, the value to check if it already exists.
	 * @return true if the value exists, false otherwise.
	 */
	private boolean contains(int row, int col, int val) {
		int regR = (int) Math.floor(row / 3);
		int regC = (int) Math.floor(col / 3);
		String regName = regR + ", " + regC;

		if (rows.containsKey(row) && rows.get(row).contains(val)) {
			return true;
		} else if (cols.containsKey(col) && cols.get(col).contains(val)) {
			return true;
		} else if (reg.containsKey(regName) && reg.get(regR + ", " + regC).contains(val)) {
			return true;
		} else {
			return false;
		}
	}
/**
 * Gets the value at the specified row/column.
 * @param row, row corresponding to the specified square.
 * @param col, column corresponding to the specified square.
 * @return The value at the square.
 */
	public int getValue(int row, int col) {
		return matrix[row][col];
	}

/**
 * Checks if the method check returns true, if it does the method solve is called from the starting position.
 * @return the value of solve if the method check returns true, otherwise false.
 */
	public boolean sudokuSolver() {
		if (check()) {
			return solve(0, 0);
		}
		return false;
	}
/**
 * Evaluates if there exists a solution from the specified square and forward using recursion.
 * @param row, row from which to check if a solution exists.
 * @param col, column from which to check if a solution exists.
 * @return true if a solution to the rest Sudoku exists, false otherwise.
 */
	
	private boolean solve(int row, int col) {

		int nextRowPos = nextPos(row, col)[0];
		int nextColPos = nextPos(row, col)[1];

		if (getValue(row, col) != 0) {
			if (row == 8 && col == 8) {
				return true;
			}
			return solve(nextRowPos, nextColPos);
		} else {
			for (int val = 1; val < 10; val++) {
				if (contains(row, col, val) == false) {
					setValue(row, col, val);
					if (row == 8 && col == 8) {
						return true;
					} else {
						if (solve(nextRowPos, nextColPos)) {
							return true;
						} else {
							removeValue(row, col);

						}
					}
				}
			}
		}
		return false;
	}



}



package sudoku;

import static org.junit.Assert.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

//import queue_delegate.FifoQueue;

import java.util.NoSuchElementException;
import java.util.Queue;
import java.util.Iterator;

public class SudokuTest {
	Sudoku sud;

	@Before
	public void setUp() throws Exception {
		sud = new Sudoku();
	}

	@After
	public void tearDown() throws Exception {
		sud = null;
	}

	/* lösning till tomt sudoku */

	@Test
	public final void testSudokuEmp() {
		assertTrue(sud.sudokuSolver());
	}

	/* lösning till sudoku i figur 1 */
	@Test
	public final void testSudokuFig1() {
		sud.setValue(0, 2, 8);
		sud.setValue(0, 5, 9);
		sud.setValue(0, 7, 6);
		sud.setValue(0, 8, 2);
		sud.setValue(1, 8, 5);
		sud.setValue(2, 0, 1);
		sud.setValue(2, 2, 2);
		sud.setValue(2, 3, 5);
		sud.setValue(3, 3, 2);
		sud.setValue(3, 4, 1);
		sud.setValue(3, 7, 9);
		sud.setValue(4, 1, 5);
		sud.setValue(4, 6, 6);
		sud.setValue(5, 0, 6);
		sud.setValue(5, 7, 2);
		sud.setValue(5, 8, 8);
		sud.setValue(6, 0, 4);
		sud.setValue(6, 1, 1);
		sud.setValue(6, 3, 6);
		sud.setValue(6, 5, 8);
		sud.setValue(7, 0, 8);
		sud.setValue(7, 1, 6);
		sud.setValue(7, 4, 3);
		sud.setValue(7, 6, 1);
		sud.setValue(8, 6, 4);
		assertTrue(sud.sudokuSolver());
	}
	
	@Test
	public final void hardestSudokuTest() {
		sud.setValue(0, 0, 8);
		sud.setValue(1, 2, 3);
		sud.setValue(1, 3, 6);
		sud.setValue(2, 1, 7);
		sud.setValue(2, 4, 9);
		sud.setValue(2, 6, 2);
		sud.setValue(3, 1, 5);
		sud.setValue(3, 5, 7);
		sud.setValue(4, 4, 4);
		sud.setValue(4, 5, 5);
		sud.setValue(4, 6, 7);
		sud.setValue(5, 3, 1);
		sud.setValue(5, 7, 3);
		sud.setValue(6, 2, 1);
		sud.setValue(6, 7, 6);
		sud.setValue(6, 8, 8);
		sud.setValue(7, 3, 5);
		sud.setValue(7, 7, 1);
		sud.setValue(7, 2, 8);
		sud.setValue(8, 1, 9);
		sud.setValue(8, 6, 4);
		assertTrue(sud.sudokuSolver());
	}
	/* "lösning" av olösliga sudoku */
	@Test
	public final void unsolvableTest() {

		sud.setValue(0, 0, 1);
		sud.setValue(0, 5, 1);
		assertFalse(sud.sudokuSolver());

		sud = new Sudoku();

		sud.setValue(0, 0, 1);
		sud.setValue(5, 0, 1);
		assertFalse(sud.sudokuSolver());

		sud = new Sudoku();

		sud.setValue(0, 0, 1);
		sud.setValue(2, 2, 1);
		assertFalse(sud.sudokuSolver());

	}
}