Clean-up

7 files changed, 146 insertions, 53 deletions

diff --git a/Makefile b/Makefile
index 09fc878..07b5fea 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,11 @@ CFLAGS += -Werror -Wall
 
 all: solve
 
-solve: display.o
+solve: display.o update.o cell.h
+
+display.o: display.c cell.h display.h
+
+update.o: update.c cell.h display.h
 
 clean:
 	rm -f *.o solve 
diff --git a/cell.h b/cell.h
index 76ecd90..fc5f467 100644
--- a/cell.h
+++ b/cell.h
@@ -1,7 +1,16 @@
+#ifndef SUDOKU_CELL_H
+#define SUDOKU_CELL_H
+
+/* Description of a single cell on a sudoku board */
 struct cell
 {
+	/* Sovled value of this cell */
 	char val;
-	char not[9];
-} cell;
 
+	/* Array used to determine which values this cell can NOT be.
+	 * A non-zero value at index N indicates that this cell cannot have the
+	 * value N + 1 */
+	char not[9];
+};
 
+#endif /* SUDOKU_CELL_H */
diff --git a/debug.h b/debug.h
new file mode 100644
index 0000000..df0fcba
--- /dev/null
+++ b/debug.h
@@ -0,0 +1,15 @@
+#ifndef SUDOKU_DEBUG_H
+#define SUDOKU_DEBUG_H
+
+#include <stdio.h>
+
+#define NAME_CELL(x,y) ("ABCDEFGHI"[(x)]), ("123456789"[(y)])
+
+//#define DEBUG
+#ifdef DEBUG
+# define DEBUG_LOG(args...)     printf(args)
+#else
+# define DEBUG_LOG(...)
+#endif
+
+#endif /* SUDOKU_DEBUG_H */
diff --git a/display.h b/display.h
index b3b5a3d..e7cecc2 100644
--- a/display.h
+++ b/display.h
@@ -1 +1,6 @@
+#ifndef SUDOKU_DISPLAY_H
+#define SUDOKU_DISPLAY_H
+
 void display(struct cell board[9][9]);
+
+#endif /* SUDOKU_DISPLAY_H */
diff --git a/solve.c b/solve.c
index 797837d..0a1cb69 100644
--- a/solve.c
+++ b/solve.c
@@ -1,59 +1,16 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "debug.h"
+#include "update.h"
 #include "cell.h"
 #include "display.h"
 
-static const char row_letter_lookup[] = "ABCDEFGHI";
-static const char col_letter_lookup[] = "123456789";
-
-#define NAME_CELL(x,y) row_letter_lookup[x], col_letter_lookup[y]
-
-//#define DEBUG
-#ifdef DEBUG
-# define DEBUG_LOG(args...)     printf(args)
-#else
-# define DEBUG_LOG(...)
-#endif
-
-
 /*
- * FIXME rename
- * For each unsolved cell on the board, update its list of values that it
- * cannot be based on the solved cells in the same row or the same column
- * Does not attempt to solve cells
- */
-void update_not_row_col(struct cell (*b)[9][9])
-{
-	int x = 0;
-	int y = 0;
-	int i = 0;
-	int val = 0;
-
-	for (y = 0; y < 9; y++)
-	{
-		for (x = 0; x < 9; x++)
-		{
-			val = (*b)[x][y].val;
-			if (val != 0)
-			{
-				DEBUG_LOG("Update: (%d,%d) has value %d\n", x, y, val);
-				for (i = 0; i < 9; i++)
-				{
-					(*b)[i][y].not[val - 1] = 1;
-					(*b)[x][i].not[val - 1] = 1;
-				}
-			}
-		}
-	}
-}
-
-/*
- * FIXME rename
  * For all unsolved cells on the board, solve them if they have been marked as
  * impossible to be 8/9 values
  */
-int not_to_val_row_col(struct cell (*b)[9][9])
+int solve_row_col(struct cell (*b)[9][9])
 {
 	int change_count = 0;
 	int x = 0;
@@ -242,11 +199,68 @@ int cells_fill_certainties(struct cell (*b)[9][9])
 	return change_count;
 }
 
+/*
+ * Check if every cell on a board is filled.
+ * Returns -1 isf the board is not fully
+ * Returns 0 if the board is filled
+ */
+int board_is_filled(struct cell (*b)[9][9])
+{
+	int x = 0;
+	int y = 0;
+
+	for (x = 0; x < 9; x++) {
+		for (y = 0; y < 9; y++) {
+			if ((*b)[x][y].val == 0) {
+				return -1;
+			}
+		}
+	}
+	return 0;
+}
+
+int board_rows_are_solved(struct cell (*b)[9][9])
+{
+	return -1;
+}
+
+int board_cols_are_solved(struct cell (*b)[9][9])
+{
+	return -1;
+}
+
+int board_3s_are_solved(struct cell (*b)[9][9])
+{
+	return -1;
+}
+
+/*
+ * Check if a board is solved.
+ * Returns -1 isf the board is unsolved
+ * Returns 0 if the board is solved
+ */
+int board_is_solved(struct cell (*b)[9][9])
+{
+	int ret = 0;
+	ret = board_is_filled(b);
+	if (ret)
+		return ret;
+
+	ret = board_rows_are_solved(b);
+	if (ret)
+		return ret;
+
+	ret = board_cols_are_solved(b);
+	if (ret)
+		return ret;
+
+	ret = board_3s_are_solved(b);
+
+	return ret;
+}
 
 int main(int argc, char **argv)
 {
-//	int x = 0;
-//	int y = 0;
 	struct cell board[9][9];
 
 	memset(board, 0, sizeof(board));
@@ -351,13 +365,17 @@ int main(int argc, char **argv)
 		change_count = 0;
 		update_not_row_col(&board);
 		change_count += not_to_val_cell(&board);
-		change_count += not_to_val_row_col(&board);
+		change_count += solve_row_col(&board);
 		change_count += cells_fill_certainties(&board);
 		total_changes += change_count;
 //		display(board);
 	}
 
-	printf("Solution (%d changes)\n", total_changes);
+	if (board_is_solved(&board) < 0) {
+		printf("Could not solve the board! Here is the closest (%d changes)\n", total_changes);
+	} else {
+		printf("Solution (%d changes)\n", total_changes);
+	}
 	display(board);
 
 }
diff --git a/update.c b/update.c
new file mode 100644
index 0000000..57c5dda
--- /dev/null
+++ b/update.c
@@ -0,0 +1,34 @@
+#include "cell.h"
+#include "debug.h"
+
+/*
+ * update_not_row_col
+ *
+ * For each unsolved cell on the board, update its list of values that it
+ * cannot be based on the solved cells in the same row or the same column
+ * Does not attempt to solve cells
+ */
+void update_not_row_col(struct cell (*b)[9][9])
+{
+	int x = 0;
+	int y = 0;
+	int i = 0;
+	int val = 0;
+
+	for (y = 0; y < 9; y++)
+	{
+		for (x = 0; x < 9; x++)
+		{
+			val = (*b)[x][y].val;
+			if (val != 0)
+			{
+				DEBUG_LOG("Update: (%d,%d) has value %d\n", x, y, val);
+				for (i = 0; i < 9; i++)
+				{
+					(*b)[i][y].not[val - 1] = 1;
+					(*b)[x][i].not[val - 1] = 1;
+				}
+			}
+		}
+	}
+}
diff --git a/update.h b/update.h
new file mode 100644
index 0000000..8bd67b6
--- /dev/null
+++ b/update.h
@@ -0,0 +1,8 @@
+#ifndef SUDOKU_UPDATE_H
+#define SUDOKU_UPDATE_H
+
+#include "cell.h"
+
+void update_not_row_col(struct cell (*)[9][9]);
+
+#endif /* SUDOKU_UPDATE_H */