Watchexec targets modified in justfile

.gitignore

@@ -5,3 +5,4 @@
 build
 
 .vscode
+app/bin

Justfile

@@ -11,7 +11,7 @@ clean:
     fd -td -I build -x rm -r
 
 watch:
-    watchexec -c -w app/src "just test && just run" 
+    watchexec -r -c -w app/src "just test && just run" 
 
 watchdoc:
-    watchexec -c -w app/src "just doc"
+    watchexec -r -c -w app/src "just doc"

app/sample_sudokus/testfall_3.txt

@@ -0,0 +1,9 @@
+1 2 3 0 0 0 0 0 0 
+4 5 6 0 0 0 0 0 0
+0 0 0 7 0 0 0 0 0
+0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0 0
+0 0 0 0 0 0 0 0 0

app/sample_sudokus/testfall_5.txt

@@ -0,0 +1,9 @@
+0 0 8 0 0 9 0 6 2
+0 0 0 0 0 0 0 0 5
+1 0 2 5 0 0 0 0 0
+0 0 0 2 1 0 0 9 0
+0 5 0 0 0 0 6 0 0
+6 0 0 0 0 0 0 2 8
+4 1 0 6 0 8 0 0 0
+8 6 0 0 3 0 1 0 0
+0 0 0 0 0 0 4 0 0

app/src/main/java/gui/SudokuController.java

@@ -25,10 +25,16 @@ public class SudokuController {
             @Override
             public void actionPerformed(ActionEvent e) {
                 // Solve the board
-                model.solve();
-
+                boolean solved = model.solve();
                 // Update the view
                 view.updateView(model.getBoard());
+                if (!solved) {
+                    view.showErrorMessage("Could not solve the board.");
+                    System.out.println("Could not solve the board.");
+                    System.out.println(model.toString());
+                } else {
+                }
+
             }
         });
 
@@ -64,6 +70,13 @@ public class SudokuController {
                 if (newBoard != null) {
                     // Set the model
                     model.setBoard(newBoard);
+
+                    // Warn and clear if the board is not solvable
+                    if(!model.isSolvable()) {
+                        view.showErrorMessage("The board is not solvable.");
+                        model.clear();
+                    }
+
                     // Update the view
                     view.updateView(model.getBoard());
                 }
@@ -88,14 +101,33 @@ public class SudokuController {
             int row = view.getSelectedRow();
             int col = view.getSelectedColumn();
 
-            int value = Integer.parseInt(view.getCellValue(row, col));
-            // Check if the input is legal and update the model and view
-            if (model.isLegal(row, col, value)) {
-                model.set(row, col, value);
-                view.updateView(model.getBoard());
+            // The value to be inserted into the cell
+            // Zero inicates an empty cell
+            // Negative values are invalid
+            int value = 0;
+
+            String cellValue = view.getCellValue(row, col);
+
+            // We need to check for null and empty string
+            if (cellValue == null || cellValue.equals("")) {
+                value = 0;
             } else {
+                try {
+                    value = Integer.parseInt(cellValue);
+                } catch (NumberFormatException ex) {
+                    value = -1;
+                }
+            }
+
+            // If the input is invalid, value < 0 indicates parse error
+            if (value != 0 && !model.isLegal(row, col, value) || value < 0) {
+                value = 0;
                 view.showErrorMessage("Invalid input. Try again.");
             }
+
+            // Update the model and view
+            model.set(row, col, value);
+            view.updateView(model.getBoard());
         }
     }
 }

app/src/main/java/sudoku/Solver.java

@@ -29,7 +29,12 @@ public class Solver implements SudokuSolver {
     /** Resets the board to all zeros */
     @Override
     public void clear() {
-        board = new int[9][9];
+        for (int[] row : board) {
+            for (int i = 0; i < row.length; ++i) {
+                row[i] = 0;
+            }
+        }
+        // board = new int[9][9];
     }
 
     /* {@inheritDoc} */
@@ -144,6 +149,11 @@ public class Solver implements SudokuSolver {
             return false;
         }
 
+        // Ihe the number is already present in the cell
+        if (board[row][col] == num) {
+            return true;
+        }
+
         // Check both the row and column
         for (int i = 0; i < 9; i++) {
             if (board[row][i] == num || board[i][col] == num) {

app/src/test/java/sudoku/SolverTest.java

@@ -86,7 +86,7 @@ class SolverTest {
     @Test
     void unsolvableTest() {
         Solver solver = new Solver();
-        
+
         // Simple example
         solver.clear();
         solver.set(0, 0, 1);
@@ -107,6 +107,37 @@ class SolverTest {
         assertFalse(solver.solve());
     }
 
+    @Test
+    void unsolvableTestCase3() {
+        Solver solver = new Solver();
+
+        // More complex example
+        solver.clear();
+        solver.set(0, 0, 1);
+        solver.set(0, 1, 2);
+        solver.set(0, 2, 3);
+        solver.set(1, 0, 4);
+        solver.set(1, 1, 5);
+        solver.set(1, 2, 6);
+        solver.set(2, 3, 7);
+        assertFalse(solver.isSolvable());
+    }
+
+    @Test
+    void solvableTestCase3() {
+        Solver solver = new Solver();
+
+        // More complex example
+        solver.clear();
+        solver.set(0, 0, 1);
+        solver.set(0, 1, 2);
+        solver.set(0, 2, 3);
+        solver.set(1, 0, 4);
+        solver.set(1, 1, 5);
+        solver.set(1, 2, 6);
+        assertTrue(solver.isSolvable());
+    }
+
     @Test
     void setBoardInvalidInputThrowsTest() {
         Solver solver = new Solver();