Here's what Bard said:
Here are some suggestions for improving your Sudoku solver code:
Use a more descriptive name for the solve() function. Something like solveSudoku() would be more clear.
The solved?() function should be renamed to isSolved().
The generateValidBranches() function should be renamed to generateValidSubboards().
The generateValidSubboards() function should be refactored to use a recursive function. This would make it easier to read and understand.
The solve() function should be refactored to use a loop that calls the generateValidSubboards() function. This would make it more efficient.
The solve() function should be tested with a variety of Sudoku puzzles to make sure it works correctly.
Here is an example of how the code could be refactored:
Code snippet
public int[][] solveSudoku(int[][] board) {
if (isSolved(board)) {
return board;
}
List<int[][]> subBoards = generateValidSubboards(board);
for (int[][] subBoard : subBoards) {
int[][] solution = solveSudoku(subBoard);
if (solution != null) {
return solution;
}
}
return null;
}
private boolean isSolved(int[][] board) {
for (int i = 0; i < board.length; i++) {
for (int j = 0; j < board[0].length; j++) {
if (board[i][j] == 0) {
return false;
}
}
}
return true;
}
private List<int[][]> generateValidSubboards(int[][] board) {
List<int[][]> subBoards = new ArrayList<>();
for (int i = 0; i < board.length; i += 3) {
for (int j = 0; j < board[0].length; j += 3) {
int[][] subBoard = new int[3][3];
for (int k = 0; k < 3; k++) {
for (int l = 0; l < 3; l++) {
subBoard[k][l] = board[i + k][j + l];
}
}
subBoards.add(subBoard);
}
}
return subBoards;
}
This code is more readable and easier to understand. It is also more efficient, as it only generates the subboards that are actually needed.