From f84cccc1b510ade19bc445249fef6dadc47a82af Mon Sep 17 00:00:00 2001
From: Imbus <imbus64@protonmail.com>
Date: Tue, 5 Dec 2023 16:13:57 +0100
Subject: [PATCH 1/2] Better comments

---
 app/src/main/java/sudoku/Solver.java | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/app/src/main/java/sudoku/Solver.java b/app/src/main/java/sudoku/Solver.java
index 1fea9c7..0d5ca47 100644
--- a/app/src/main/java/sudoku/Solver.java
+++ b/app/src/main/java/sudoku/Solver.java
@@ -38,6 +38,7 @@ public class Solver implements SudokuSolver {
             return false;
         }
 
+        // If row is 9, drop down to the next column, if column is 9, we are done
         if (row == 9) {
             row = 0;
             if (++col == 9) {
@@ -45,13 +46,17 @@ public class Solver implements SudokuSolver {
             }
         }
 
+        // If we have a "number" in the current cell
+        // recursively call solve() on the next cell
         if (board[row][col] != 0) {
             return solve(row + 1, col);
         }
 
+        // Check for legal values in the current cell
         for (int val = 1; val <= 9; ++val) {
             if (legal(row, col, val)) {
                 board[row][col] = val;
+                // When we find a legal value, recursively call solve() on the next cell
                 if (solve(row + 1, col)) {
                     return true;
                 }

From 56ab2ca98fe78a0c16f935853707590af0243768 Mon Sep 17 00:00:00 2001
From: Imbus <imbus64@protonmail.com>
Date: Tue, 5 Dec 2023 16:51:55 +0100
Subject: [PATCH 2/2] Better docstrings

---
 app/src/main/java/sudoku/Solver.java | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/app/src/main/java/sudoku/Solver.java b/app/src/main/java/sudoku/Solver.java
index 0d5ca47..c171c8a 100644
--- a/app/src/main/java/sudoku/Solver.java
+++ b/app/src/main/java/sudoku/Solver.java
@@ -7,10 +7,16 @@ public class Solver implements SudokuSolver {
         board = new int[9][9];
     }
 
+    /**
+     * {@inheritDoc}
+     */
     public void setBoard(int[][] board) {
         this.board = board;
     }
 
+    /**
+     * {@inheritDoc}
+     */
     public int[][] getBoard() {
         return board;
     }
@@ -22,6 +28,9 @@ public class Solver implements SudokuSolver {
         board = new int[9][9];
     }
 
+    /**
+     * {@inheritDoc}
+     */
     public boolean solve() {
         return solve(0, 0);
     }
@@ -96,12 +105,7 @@ public class Solver implements SudokuSolver {
     }
 
     /**
-     * Checks if val is legal in the given row, column, and 3x3 box
-     * 
-     * @param row row to check
-     * @param col column to check
-     * @param val value to check
-     * @return true if val is legal
+     * {@inheritDoc}
      */
     public boolean legal(int row, int col, int val) {
         if (row < 0 || row >= 9 || col < 0 || col >= 9 || val < 1 || val > 9) {
@@ -138,6 +142,11 @@ public class Solver implements SudokuSolver {
         return true;
     }
 
+    /**
+     * Checks if the board is solved
+     * 
+     * @return true if solved
+     */
     public boolean isSolved() {
         return isSolved(0, 0);
     }
@@ -147,7 +156,7 @@ public class Solver implements SudokuSolver {
      * 
      * @param row
      * @param col
-     * @return
+     * @return true if solved
      */
     private boolean isSolved(int row, int col) {
         // If we are at the 9th row and 0th column (the last cell), we are done