diff --git a/pom.xml b/pom.xml
index e365be3f3f96..b7a8e68811a5 100644
--- a/pom.xml
+++ b/pom.xml
@@ -100,23 +100,35 @@
- org.apache.maven.plugins
- maven-checkstyle-plugin
- 3.6.0
-
- checkstyle.xml
- true
- true
- warning
-
-
-
- com.puppycrawl.tools
- checkstyle
- 11.0.0
-
-
-
+ org.apache.maven.plugins
+ maven-checkstyle-plugin
+ 3.6.0
+
+
+ checkstyle
+ verify
+
+ check
+
+
+ checkstyle.xml
+ true
+ true
+ warning
+
+ false
+
+
+
+
+
+ com.puppycrawl.tools
+ checkstyle
+ 11.0.0
+
+
+
+
com.github.spotbugs
spotbugs-maven-plugin
diff --git a/src/main/java/com/thealgorithms/puzzlesandgames/Sudoku.java b/src/main/java/com/thealgorithms/puzzlesandgames/Sudoku.java
index fce665c4de00..db9ff1aa750f 100644
--- a/src/main/java/com/thealgorithms/puzzlesandgames/Sudoku.java
+++ b/src/main/java/com/thealgorithms/puzzlesandgames/Sudoku.java
@@ -1,3 +1,4 @@
+
package com.thealgorithms.puzzlesandgames;
/**
diff --git a/src/main/java/com/thealgorithms/puzzlesandgames/SudokuBoard.java b/src/main/java/com/thealgorithms/puzzlesandgames/SudokuBoard.java
new file mode 100644
index 000000000000..76d12da45ea1
--- /dev/null
+++ b/src/main/java/com/thealgorithms/puzzlesandgames/SudokuBoard.java
@@ -0,0 +1,223 @@
+package com.thealgorithms.puzzlesandgames;
+
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ * Represents a Sudoku board with validation and iteration support.
+ * The board is always a square grid of size n x n,
+ * where n must be a perfect square (e.g., 4, 9, 16).
+ */
+public class SudokuBoard implements Iterable {
+
+ private final int size;
+ private final int boxSize;
+ private final int[][] board;
+
+ /**
+ * Constructs a SudokuBoard of the given size.
+ *
+ * @param size the dimension of the Sudoku board (must be a perfect square)
+ * @throws IllegalArgumentException if size is not a positive perfect square
+ */
+ public SudokuBoard(int size) {
+ if (size <= 0 || Math.sqrt(size) % 1 != 0) {
+ throw new IllegalArgumentException("Size must be a perfect square (e.g., 4, 9, 16)");
+ }
+ this.size = size;
+ this.boxSize = (int) Math.sqrt(size);
+ this.board = new int[size][size];
+ }
+
+ /**
+ * Returns the size of the board.
+ *
+ * @return the board size
+ */
+ public int getSize() {
+ return size;
+ }
+
+ /**
+ * Returns the box (subgrid) size.
+ *
+ * @return the size of a subgrid
+ */
+ public int getBoxSize() {
+ return boxSize;
+ }
+
+ /**
+ * Gets the value at the given cell.
+ *
+ * @param row the row index
+ * @param col the column index
+ * @return the value at the specified cell
+ * @throws IndexOutOfBoundsException if indices are invalid
+ */
+ public int get(int row, int col) {
+ validateCell(row, col);
+ return board[row][col];
+ }
+
+ /**
+ * Sets the value at the given cell.
+ *
+ * @param row the row index
+ * @param col the column index
+ * @param value the value to set (0 means empty)
+ * @throws IndexOutOfBoundsException if indices are invalid
+ * @throws IllegalArgumentException if value is out of range
+ */
+ public void set(int row, int col, int value) {
+ validateCell(row, col);
+ if (value < 0 || value > size) {
+ throw new IllegalArgumentException("Value must be between 0 and " + size);
+ }
+ board[row][col] = value;
+ }
+
+ /**
+ * Checks whether placing a value at the given cell is valid
+ * according to Sudoku rules.
+ *
+ * @param row the row index
+ * @param col the column index
+ * @param value the value to check
+ * @return true if placement is valid, false otherwise
+ */
+ public boolean isValid(int row, int col, int value) {
+ validateCell(row, col);
+ if (value <= 0 || value > size) {
+ return false;
+ }
+
+ // check row
+ for (int c = 0; c < size; c++) {
+ if (board[row][c] == value) {
+ return false;
+ }
+ }
+
+ // check column
+ for (int r = 0; r < size; r++) {
+ if (board[r][col] == value) {
+ return false;
+ }
+ }
+
+ // check box
+ int boxRowStart = (row / boxSize) * boxSize;
+ int boxColStart = (col / boxSize) * boxSize;
+
+ for (int r = 0; r < boxSize; r++) {
+ for (int c = 0; c < boxSize; c++) {
+ if (board[boxRowStart + r][boxColStart + c] == value) {
+ return false;
+ }
+ }
+ }
+
+ return true;
+ }
+
+ /**
+ * Ensures that the given cell indices are valid.
+ *
+ * @param row the row index
+ * @param col the column index
+ * @throws IndexOutOfBoundsException if indices are outside the board
+ */
+ private void validateCell(int row, int col) {
+ if (row < 0 || row >= size || col < 0 || col >= size) {
+ throw new IndexOutOfBoundsException("Cell position out of bounds");
+ }
+ }
+
+ /**
+ * Represents a single cell on the Sudoku board.
+ */
+ public class Cell {
+ private final int row;
+ private final int col;
+
+ /**
+ * Constructs a Cell with the given row and column.
+ *
+ * @param row the row index
+ * @param col the column index
+ */
+ public Cell(int row, int col) {
+ this.row = row;
+ this.col = col;
+ }
+
+ /**
+ * Returns the row index of this cell.
+ *
+ * @return the row index
+ */
+ public int getRow() {
+ return row;
+ }
+
+ /**
+ * Returns the column index of this cell.
+ *
+ * @return the column index
+ */
+ public int getCol() {
+ return col;
+ }
+
+ /**
+ * Gets the current value stored in this cell.
+ *
+ * @return the cell value
+ */
+ public int getValue() {
+ return board[row][col];
+ }
+
+ /**
+ * Sets a value in this cell.
+ *
+ * @param value the value to set
+ */
+ public void setValue(int value) {
+ SudokuBoard.this.set(row, col, value);
+ }
+ }
+
+ /**
+ * Iterator for traversing all cells in the board.
+ */
+ private class CellIterator implements Iterator {
+ private int row = 0;
+ private int col = 0;
+
+ @Override
+ public boolean hasNext() {
+ return row < size;
+ }
+
+ @Override
+ public Cell next() {
+ if (!hasNext()) {
+ throw new NoSuchElementException();
+ }
+ Cell cell = new Cell(row, col);
+ col++;
+ if (col == size) {
+ col = 0;
+ row++;
+ }
+ return cell;
+ }
+ }
+
+ @Override
+ public Iterator| iterator() {
+ return new CellIterator();
+ }
+}
| |