org.chocosolver.examples.integer.Sudoku Maven / Gradle / Ivy
/*
* This file is part of examples, http://choco-solver.org/
*
* Copyright (c) 2021, IMT Atlantique. All rights reserved.
*
* Licensed under the BSD 4-clause license.
*
* See LICENSE file in the project root for full license information.
*/
package org.chocosolver.examples.integer;
import org.chocosolver.examples.AbstractProblem;
import org.chocosolver.solver.Model;
import org.chocosolver.solver.exception.ContradictionException;
import org.chocosolver.solver.variables.IntVar;
import org.kohsuke.args4j.Option;
import static org.chocosolver.solver.search.strategy.Search.minDomLBSearch;
import static org.chocosolver.util.tools.ArrayUtils.append;
/**
* wikipedia:
* "The objective is to fill a 9?9 grid with digits so that
* each column, each row, and each of the nine 3?3 sub-grids that compose the grid
* contains all of the digits from 1 to 9.
* The puzzle setter provides a partially completed grid, which typically has a unique solution."
*
*
* @author Charles Prud'homme
* @since 19/04/11
*/
public class Sudoku extends AbstractProblem {
@Option(name = "-g", aliases = "--grid", usage = "Sudoku grid ID.", required = false)
Data data = Data.level1;
private final int n = 9;
IntVar[][] rows, cols, carres;
@Override
public void buildModel() {
model = new Model();
rows = new IntVar[n][n];
cols = new IntVar[n][n];
carres = new IntVar[n][n];
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
if (data.grid(i, j) > 0) {
rows[i][j] = model.intVar(data.grid(i, j));
} else {
rows[i][j] = model.intVar("c_" + i + "_" + j, 1, n, false);
}
cols[j][i] = rows[i][j];
}
}
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++) {
for (int k = 0; k < 3; k++) {
carres[j + k * 3][i] = rows[k * 3][i + j * 3];
carres[j + k * 3][i + 3] = rows[1 + k * 3][i + j * 3];
carres[j + k * 3][i + 6] = rows[2 + k * 3][i + j * 3];
}
}
}
for (int i = 0; i < n; i++) {
model.allDifferent(rows[i], "AC").post();
model.allDifferent(cols[i], "AC").post();
model.allDifferent(carres[i], "AC").post();
}
}
@Override
public void configureSearch() {
model.getSolver().setSearch(minDomLBSearch(append(rows)));
}
@Override
public void solve() {
// model.getSolver().showStatistics();
// model.getSolver().solve();
try {
model.getSolver().propagate();
} catch (ContradictionException e) {
e.printStackTrace();
}
StringBuilder st = new StringBuilder(String.format("Sudoku -- %s\n", data.name()));
st.append("\t");
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
st.append(rows[i][j]).append("\t\t\t");
}
st.append("\n\t");
}
System.out.println(st.toString());
}
public static void main(String[] args) {
new Sudoku().execute(args);
}
/////////////////////////////////// DATA //////////////////////////////////////////////////
enum Data {
level1(
new int[][]{
{0, 0, 0, 2, 0, 0, 0, 0, 0},
{0, 8, 0, 0, 3, 0, 0, 7, 0},
{3, 0, 0, 5, 0, 4, 0, 0, 0},
{0, 0, 0, 0, 0, 0, 0, 2, 8},
{8, 3, 0, 0, 1, 0, 0, 0, 0},
{0, 4, 0, 7, 2, 0, 3, 5, 1},
{0, 7, 0, 0, 5, 6, 0, 0, 4},
{0, 0, 3, 0, 0, 0, 0, 0, 0},
{2, 0, 5, 4, 0, 1, 6, 0, 3}
}
),
level2(
new int[][]{
{3, 0, 4, 0, 2, 0, 0, 7, 0},
{1, 5, 0, 0, 0, 0, 0, 4, 0},
{0, 0, 0, 0, 0, 1, 0, 8, 3},
{0, 0, 0, 0, 0, 6, 1, 0, 0},
{2, 0, 5, 0, 3, 0, 0, 0, 8},
{7, 0, 0, 1, 0, 0, 3, 0, 0},
{0, 0, 0, 0, 0, 0, 6, 0, 0},
{5, 6, 0, 0, 0, 7, 0, 0, 0},
{0, 0, 0, 8, 0, 0, 0, 1, 4}
}
),
level3(
new int[][]{
{0, 1, 0, 0, 0, 0, 0, 0, 0},
{8, 0, 0, 0, 0, 2, 1, 7, 0},
{0, 0, 4, 0, 0, 0, 0, 0, 0},
{0, 2, 0, 0, 0, 6, 0, 1, 3},
{0, 5, 3, 0, 7, 0, 6, 0, 2},
{1, 0, 0, 8, 0, 0, 5, 4, 0},
{0, 0, 0, 3, 1, 5, 0, 2, 6},
{0, 4, 0, 2, 0, 0, 0, 0, 7},
{0, 0, 0, 4, 8, 0, 3, 0, 0}
}
),
level4(
new int[][]{
{0, 4, 0, 8, 0, 0, 0, 0, 0},
{0, 1, 0, 7, 2, 0, 5, 0, 4},
{8, 0, 0, 4, 0, 0, 0, 0, 0},
{1, 0, 5, 3, 0, 0, 4, 2, 0},
{0, 3, 0, 0, 0, 0, 0, 0, 0},
{4, 0, 0, 0, 5, 0, 7, 0, 1},
{6, 0, 0, 0, 0, 0, 1, 7, 0},
{0, 0, 0, 2, 1, 0, 8, 6, 0},
{2, 0, 0, 0, 3, 7, 0, 0, 0}
}
),
level5(
new int[][]{
{0, 0, 0, 2, 0, 0, 0, 1, 5},
{3, 0, 0, 0, 0, 0, 7, 8, 0},
{0, 0, 0, 7, 0, 0, 0, 0, 0},
{1, 0, 0, 0, 0, 0, 0, 5, 7},
{7, 2, 0, 0, 4, 0, 0, 0, 0},
{8, 6, 0, 1, 0, 3, 0, 4, 0},
{4, 0, 0, 0, 1, 0, 0, 0, 0},
{2, 1, 0, 0, 0, 7, 8, 3, 0},
{0, 5, 0, 3, 0, 0, 0, 0, 0}
}
),
level6(
new int[][]{
{0, 0, 0, 1, 0, 5, 4, 0, 0},
{0, 6, 0, 2, 0, 8, 0, 0, 7},
{0, 5, 2, 0, 0, 0, 1, 0, 0},
{0, 1, 5, 6, 0, 2, 0, 0, 0},
{2, 0, 0, 0, 0, 7, 5, 1, 0},
{0, 7, 8, 4, 0, 0, 0, 3, 2},
{0, 0, 3, 0, 1, 4, 7, 0, 6},
{0, 0, 0, 0, 0, 0, 0, 0, 0},
{6, 0, 0, 5, 0, 0, 0, 8, 0}
}
),;
final int[][] grid;
Data(int[][] grid) {
this.grid = grid;
}
int grid(int i, int j) {
return grid[i][j];
}
}
}
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