Merge pull request #2 from timlg07/praktomat-specific-version

timlg07 · web-flow · commit eac57239135b · 2020-06-28T16:27:39.000+02:00
Praktomat specific version
diff --git a/.gitignore b/.gitignore
@@ -84,4 +84,5 @@ local.properties
 
 # Uncomment this line if you wish to ignore the project description file.
 # Typically, this file would be tracked if it contains build/dependency configurations:
-#.project
+#.project
+countLines.cmd
diff --git a/Sudoku-Solver/src/sudoku/io/Shell.java b/Sudoku-Solver/src/sudoku/io/Shell.java
@@ -1,19 +1,18 @@
-package de.tim_greller.sudoku.io;
+package sudoku.io;
 
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStreamReader;
-import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
-import de.tim_greller.sudoku.model.Board;
-import de.tim_greller.sudoku.model.EnforcedCell;
-import de.tim_greller.sudoku.model.EnforcedNumber;
-import de.tim_greller.sudoku.model.InvalidSudokuException;
-import de.tim_greller.sudoku.model.SudokuBoardSolver;
-import de.tim_greller.sudoku.model.SudokuSolver;
+import sudoku.model.Board;
+import sudoku.model.EnforcedCell;
+import sudoku.model.EnforcedNumber;
+import sudoku.model.InvalidSudokuException;
+import sudoku.model.SudokuBoardSolver;
+import sudoku.model.SudokuSolver;
 
 /**
  * The shell class handles the interaction between the user and the data model
@@ -53,11 +52,11 @@ public static void main(String[] args) throws IOException {
     }
 
     /**
-     * Reads the next input line and initiates the execution of it.
-     * Returns {@code false} if EOF is reached.
-     * Performs no operation for blank lines.
+     * Interprets the given line of user input and initiates the execution of
+     * it. Returns {@code false} if EOF is reached and Performs no operation for
+     * blank lines.
      * 
-     * @param stdin The BufferedReader for the standard input stream.
+     * @param line The line that should be processed.
      * @return whether the program should continue execution or terminate after 
      *         the current line of input is processed.
      */
@@ -99,20 +98,24 @@ private static boolean executeCommand(String[] tokenizedInput) {
             break;
             
         case "saturate":
-            saturateSudoku();
+            printSaturatedSudoku();
             break;
             
         case "first":
-            solveSudoku();
+            printSolvedSudoku();
             break;
             
         case "all":
             printAllSolutions();
             break;
             
+        case "help":
+            printHelpText();
+            break;
+            
         case "print":
             if (requireLoadedBoard()) {
-                prettyPrint(currentBoard);
+                System.out.println(currentBoard.prettyPrint());
             }
             break;
             
@@ -126,7 +129,7 @@ private static boolean executeCommand(String[] tokenizedInput) {
         
         return true;
     }
-    
+
     /**
      * Prints all possible solutions of the currently loaded board with one
      * solution per line.
@@ -135,31 +138,47 @@ private static void printAllSolutions() {
         if (requireLoadedBoard()) {
             List<Board> solutions 
                 = currentSolver.findAllSolutions(currentBoard);
-            Collections.sort(solutions);
             
-            // Join the string representation of all sudokus.
-            String output = solutions.stream()
-                                     .map(Board::toString)
-                                     .collect(Collectors.joining("\n"));
-
-            System.out.println(output);
+            if (solutions.size() == 0) {
+                printError("This board is unsolvable");
+            } else {
+            
+                // Sort all sudokus and join their string representation.
+                String output = solutions.stream()
+                                         .sorted()
+                                         .map(Board::toString)
+                                         .collect(Collectors.joining("\n"));
+                
+                System.out.println(output);
+            }
         }
     }
 
-    private static void solveSudoku() {
+    /**
+     * Prints the first found solution using pretty print.
+     */
+    private static void printSolvedSudoku() {
         if (requireLoadedBoard()) {
             Board solvedBoard = currentSolver.findFirstSolution(currentBoard);
-            prettyPrint(solvedBoard);
+            prettyPrintSolved(solvedBoard);
         }
     }
     
-    private static void saturateSudoku() {
+    /**
+     * Pretty prints the the sudoku after all registered saturator strategies
+     * were applied.
+     */
+    private static void printSaturatedSudoku() {
         if (requireLoadedBoard()) {
             Board saturatedBoard = currentSolver.saturate(currentBoard);
-            prettyPrint(saturatedBoard);
+            prettyPrintSolved(saturatedBoard);
         }
     }
     
+    /**
+     * Instantiates a new Solver and registers the {@link EnforcedCell} and
+     * {@link EnforcedNumber} saturators on it.
+     */
     private static void setupSolver() {
         currentSolver = new SudokuBoardSolver();
         currentSolver.addSaturator(new EnforcedCell());
@@ -211,12 +230,57 @@ private static void inputSudoku(String[] tokenizedInput) {
     }
     
     /**
-     * Prints the given {@link Board} as a rectangle.
-     * @param board The board that should be printed, not null.
+     * Prints the given {@link Board} as a rectangle. If the board is 
+     * {@code null} an error indicating that the board is unsolvable is printed.
+     * 
+     * @param board The solved board that should be printed, may be null.
+     */
+    private static void prettyPrintSolved(Board board) {
+        if (board == null) {
+            printError("This board is unsolvable");
+        } else {
+            System.out.println(board.prettyPrint());
+        }
+    }
+    
+    /**
+     * Prints the help text containing informations about the existing commands
+     * and their syntax.
      */
-    private static void prettyPrint(Board board) {
-        assert (board != null);
-        System.out.println(board.prettyPrint());
+    private static void printHelpText() {
+        System.out.println(
+                  "The sudoku shell is capable of solving every sudoku you "
+                + "load. You are not limited to standard 9 by 9 sudokus, but "
+                + "can load and solve sudokus of all sizes.\n\n"
+                + "Available commands:\n"
+                
+                + "input [[<drive>:][<path>]<filename>    Loads a sudoku from a"
+                + " sudoku file (*.sud) with the given absolute or relative "
+                + "path. Paths or filenames with spaces must be put in double "
+                + "quotes. The sudoku file has to specify the size of boxes in "
+                + "the sudoku, which is done by writing the amount of rows and "
+                + "columns in the first line, separated with a space. The "
+                + "following lines should contain one row of the sudoku per "
+                + "line as a space separated list of its cells. Empty cells are"
+                + " indicated as dots.\n"
+                
+                + "first    Computes and prints the first found solution of the"
+                + " sudoku if it is solvable.\n"
+                
+                + "all      Generates all possible sudokus and prints them "
+                + "(one sudoku per line) in ascending order.\n"
+                
+                + "saturate Prints the sudoku with all strategies applied if "
+                + "they do not lead to an unsolvable sudoku. Since this will "
+                + "not do any backtracking, the provided sudoku can, but does "
+                + "not have to be fully solved.\n"
+                
+                + "print    Prints the currently loaded sudoku.\n"
+                
+                + "help     Shows this help text.\n"
+                
+                + "quit     Exits the program.\n"
+        );
     }
 
     /**
diff --git a/Sudoku-Solver/src/sudoku/io/SudokuFileParser.java b/Sudoku-Solver/src/sudoku/io/SudokuFileParser.java
@@ -1,15 +1,15 @@
-package de.tim_greller.sudoku.io;
+package sudoku.io;
 
 import java.io.BufferedReader;
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
 import java.util.Optional;
 
-import de.tim_greller.sudoku.model.Board;
-import de.tim_greller.sudoku.model.InvalidSudokuException;
-import de.tim_greller.sudoku.model.Structure;
-import de.tim_greller.sudoku.model.SudokuBoard;
+import sudoku.model.Board;
+import sudoku.model.InvalidSudokuException;
+import sudoku.model.Structure;
+import sudoku.model.SudokuBoard;
 
 /**
  * This class provides the functionality to read a sudoku-file and generate a
diff --git a/Sudoku-Solver/src/sudoku/io/package-info.java b/Sudoku-Solver/src/sudoku/io/package-info.java
@@ -2,4 +2,4 @@
  * This package provides utility classes for I/O operations on the data model,
  * such as loading a sudoku from a file and executing operations on it.
  */
-package de.tim_greller.sudoku.io;
+package sudoku.io;
diff --git a/Sudoku-Solver/src/sudoku/model/Board.java b/Sudoku-Solver/src/sudoku/model/Board.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 /**
  * An interface for the representation and for solving of Sudokus, which
diff --git a/Sudoku-Solver/src/sudoku/model/EnforcedCell.java b/Sudoku-Solver/src/sudoku/model/EnforcedCell.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 /**
  * A solution strategy that sets all cells of a sudoku that can only contain one
diff --git a/Sudoku-Solver/src/sudoku/model/EnforcedNumber.java b/Sudoku-Solver/src/sudoku/model/EnforcedNumber.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 /**
  * A solution strategy that sets all cells of a sudoku which have to contain a
@@ -39,16 +39,16 @@ public boolean saturate(Board board) throws UnsolvableSudokuException {
     private boolean saturateStructure(Board board, Structure struct, int major) 
             throws UnsolvableSudokuException {
         boolean modifiedBoard = false;
-        int[] amountsOfpossibleCells = computeAmounts(board, struct, major);
+        int[] amountsOfPossibleCells = computeAmounts(board, struct, major);
         
         for (int minor = 0; minor < board.getNumbers(); minor++) {
             boolean modifiedCurrentCell = false;
             int[] possibilities = board.getPossibilities(struct, major, minor);
             
             if (possibilities != null) {
                 for (int possibility : possibilities) {
-                    if (amountsOfpossibleCells[possibility - 1] == 1) {
-                        
+
+                    if (amountsOfPossibleCells[possibility - 1] == 1) {
                         if (modifiedCurrentCell) {
                             /*
                              * Two values in this structure can only be assigned
@@ -63,7 +63,7 @@ private boolean saturateStructure(Board board, Structure struct, int major)
                         } catch (InvalidSudokuException e) {
                             throw new UnsolvableSudokuException();
                         }
-                        
+
                         modifiedCurrentCell = true;
                         modifiedBoard = true;
                     }
diff --git a/Sudoku-Solver/src/sudoku/model/InvalidSudokuException.java b/Sudoku-Solver/src/sudoku/model/InvalidSudokuException.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 /**
  * Exception if one likes to set a number which is not possible.
diff --git a/Sudoku-Solver/src/sudoku/model/Saturator.java b/Sudoku-Solver/src/sudoku/model/Saturator.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 /**
  * An interface which must be implemented by classes which provide a solution
diff --git a/Sudoku-Solver/src/sudoku/model/Structure.java b/Sudoku-Solver/src/sudoku/model/Structure.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 /**
  * The different types of structures/coordinate systems.
diff --git a/Sudoku-Solver/src/sudoku/model/SudokuBoard.java b/Sudoku-Solver/src/sudoku/model/SudokuBoard.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 import java.util.BitSet;
 
@@ -42,6 +42,10 @@ public SudokuBoard(int boxRows, int boxCols) {
      * <p>Setting a cells content to a number removes this number from the 
      * possible values in all other cells sharing a structure with the specified
      * cell.</p>
+     * <p>A sudoku is seen as unsolvable if and only if a structure contains a
+     * duplicate or a cell that can not be set to any number without causing a 
+     * duplicate. It does not check if every structure can contain all numbers.
+     * </p>
      * 
      * @throws IllegalStateException Trying to overwrite a fixed cell.
      */
@@ -77,7 +81,7 @@ public void setCell(Structure struct, int major, int minor, int number)
             }
         }
     }
-    
+
     /**
      * {@inheritDoc}
      * Does nothing if the cell is already set to a fixed value.
diff --git a/Sudoku-Solver/src/sudoku/model/SudokuBoardSolver.java b/Sudoku-Solver/src/sudoku/model/SudokuBoardSolver.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 import java.util.ArrayList;
 import java.util.Deque;
@@ -68,7 +68,7 @@ private void saturateDirect(Board board) throws UnsolvableSudokuException {
      */
     @Override
     public Board findFirstSolution(Board board) {
-        return solve(board, false).get(0);
+        return solve(board, false).stream().findFirst().orElse(null);
     }
 
     /**
@@ -128,12 +128,13 @@ private List<Board> generateCandidates(Board board) {
     
     /**
      * Tries to solve a given sudoku using backtracking. The saturators are used
-     * to speed up the process of sorting out wrong boards.
+     * to speed up the process of sorting out unsolvable boards.
      * 
      * @param board The sudoku that should be solved. Will not be changed.
      * @param requestAllSolutions Whether all solutions are needed or one is
      *        sufficient.
      * @return A List containing one or, if requested, all solutions of board.
+     *         For unsolvable sudokus an empty list is returned.
      */
     private List<Board> solve(Board board, boolean requestAllSolutions) {
         List<Board> solutions = new LinkedList<Board>();
diff --git a/Sudoku-Solver/src/sudoku/model/SudokuSolver.java b/Sudoku-Solver/src/sudoku/model/SudokuSolver.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 import java.util.List;
 
diff --git a/Sudoku-Solver/src/sudoku/model/UnsolvableSudokuException.java b/Sudoku-Solver/src/sudoku/model/UnsolvableSudokuException.java
@@ -1,4 +1,4 @@
-package de.tim_greller.sudoku.model;
+package sudoku.model;
 
 /**
  * Exception if board gets unsolvable.
diff --git a/Sudoku-Solver/src/sudoku/model/package-info.java b/Sudoku-Solver/src/sudoku/model/package-info.java
@@ -3,4 +3,4 @@
  * can be used to store and solve sudokus. To enable simple communication with
  * this model, it contains custom exception- and enumeration-classes.
  */
-package de.tim_greller.sudoku.model;
+package sudoku.model;
diff --git a/Sudoku-Solver/sudokus/impossible.sud b/Sudoku-Solver/sudokus/impossible.sud
@@ -0,0 +1,5 @@
+2 2
+. . . .
+1 . . .
+. 3 . .
+. 4 . .
diff --git a/Sudoku-Solver/sudokus/negative.sud b/Sudoku-Solver/sudokus/negative.sud
@@ -0,0 +1 @@
+-1 -1
diff --git a/Sudoku-Solver/sudokus/no.sud b/Sudoku-Solver/sudokus/no.sud
@@ -0,0 +1 @@
+0 0
diff --git a/Sudoku-Solver/sudokus/smol.sud b/Sudoku-Solver/sudokus/smol.sud
@@ -0,0 +1,2 @@
+1 1
+.
diff --git a/Tests.txt b/Tests.txt

Original file line number	Diff line number	Diff line change
`@@ -1,4 +1,4 @@`
`1`		`-package de.tim_greller.sudoku.model;`
	`1`	`+package sudoku.model;`
`2`	`2`
`3`	`3`	`/**`
`4`	`4`	`* An interface for the representation and for solving of Sudokus, which`
-Original file line number
+Diff line change
@@ @@ -0,0 +1,5 @@ @@
 +2 2
 +. . . .
 +1 . . .
 +. 3 . .
 +. 4 . .