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xternal_sudoku.c
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1/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
2/* */
3/* This file is part of the program and library */
4/* SCIP --- Solving Constraint Integer Programs */
5/* */
6/* Copyright (c) 2002-2023 Zuse Institute Berlin (ZIB) */
7/* */
8/* Licensed under the Apache License, Version 2.0 (the "License"); */
9/* you may not use this file except in compliance with the License. */
10/* You may obtain a copy of the License at */
11/* */
12/* http://www.apache.org/licenses/LICENSE-2.0 */
13/* */
14/* Unless required by applicable law or agreed to in writing, software */
15/* distributed under the License is distributed on an "AS IS" BASIS, */
16/* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. */
17/* See the License for the specific language governing permissions and */
18/* limitations under the License. */
19/* */
20/* You should have received a copy of the Apache-2.0 license */
21/* along with SCIP; see the file LICENSE. If not visit scipopt.org. */
22/* */
23/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
24
25/**@file examples/Sudoku/doc/xternal_sudoku.c
26 * @brief main document page
27 * @author Naga V C Gudapati
28 */
29
30/*--+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8----+----9----+----0----+----1----+----2*/
31
32/**@page SUDOKU_MAIN Sudoku Solver
33 * @author Naga V C Gudapati
34 *
35 * Methodology
36 * ============
37 *
38 * To solve the given sudoku puzzle using integer programming, we shall use this handy tutorial;
39 * http://profs.sci.univr.it/~rrizzi/classes/PLS2015/sudoku/doc/497_Olszowy_Wiktor_Sudoku.pdf
40 *
41 * An unsolved sudoku puzzle looks like below:<br>
42 * <tt>
43 * +----------+-----------+-----------+ <br>
44 * |* * * | * * * | * * * | <br>
45 * |* 3 * | * 1 2 | * * 8 | <br>
46 * |* 7 * | * 6 8 | * 2 * | <br>
47 * +----------+-----------+-----------+ <br>
48 * |* * * | * * 9 | 8 7 * | <br>
49 * |1 2 * | 6 5 * | 4 * * | <br>
50 * |* * * | * * * | * * 6 | <br>
51 * +----------+-----------+-----------+ <br>
52 * |* * 3 | 9 4 * | * * * | <br>
53 * |* * * | 2 * * | * 6 * | <br>
54 * |4 * * | * * * | * 3 1 | <br>
55 * +----------+-----------+-----------+ <br>
56 * </tt>
57 *
58 * The solved puzzle will have each of the nine rows and columns filled by numbers 1, ..., 9 each appearing
59 * exactly once. There are 9 subgrids and each subgrid also needs to be filled by numbers 1, ..., 9 each
60 * appearing exactly once. As seen in the unsolved puzzles, some of the positions are already filled.
61 *
62 * In this example, we see
63 * - how to model problems with many variables in SCIP,
64 * - how to set parameters
65 * - how use the solution status to print custom output messages.
66 *
67 * Data Format
68 * ============
69 *
70 * A sudoku puzzle is in represented by a string of 81 charcaters. An already filled number in the
71 * puzzle is represented by that number; a blank is represented by either '.' or '0' in the puzzle
72 * string.
73 * The input file is containing the configuration of a sudoku read rowwise as a string.
74 * For example, the above puzzle is represented by
75 * 000000000030012008070068020000009870120650400000000006003940000000200060400000031
76 * or
77 * ..........3..12..8.7..68.2......987.12.65.4..........6..394.......2...6.4......31
78 *
79 * Installation
80 * ============
81 *
82 * See the @ref INSTALL_APPLICATIONS_EXAMPLES "Install file"
83 *
84 */