#include <stdio.h>
#include "ttt-board.h"
+#include "ttt-error.h"
/* Initialize an empty board. */
void
{
board->cells[i] = TTT_CELL_EMPTY;
}
+ board->current_player = TTT_CELL_X;
}
/* Initialize a board from its string representation.
ttt_board_init_from_string (ttt_board_t *board,
const char *s)
{
- /* XXX: NYI */
+ int i, j;
+ j = 0;
+ for (i = 0; i < strlen (s); i++)
+ {
+ if ((s[i] == 'X') |
+ (s[i] == 'O') |
+ (s[i] == '_'))
+ {
+ board->cells[j] = s[i];
+ j++;
+ }
+ }
}
+
/* Return the string representation of a board.
*
* The return value is a malloc()ed string that should be free()ed
* 3|4|5
* 6|7|8
*
- * Returns: 1 if a move isa made succesfully. O if a move is invalid
- * (the given cell is not empty).
- *
- * Bugs: Currently this function always places X for all moves. So,
- * yeah, we'll need to fix that.
+ * Returns: TTT_ERROR_NONE if a move is made
+ * succesfully. TTT_ERROR_NOT_VALID_MOVE if a move is invalid (the
+ * given cell is not empty). TTT_ERROR_NOT_GRID if the move is
+ * impossible (user input 'a' or '9' etc.)
*/
-
-int ttt_board_make_move (ttt_board_t *board, int move)
-{
+ttt_error_t ttt_board_make_move (ttt_board_t *board, int move)
+{
+ if (move < 0 || move > 8)
+ return TTT_ERROR_NOT_GRID;
+
+ if (board->cells[move] != TTT_CELL_EMPTY)
+ return TTT_ERROR_NOT_VALID_MOVE;
+
+ board->cells[move] = board->current_player;
- putchar(move);
- if (board->cells[move] == '_')
+ if (board->current_player == TTT_CELL_X)
+ board->current_player = TTT_CELL_O;
+ else
+ board->current_player = TTT_CELL_X;
+ return TTT_ERROR_NONE;
+}
+
+/* Checks to see if a player has won the game and should be called
+ * after every move.
+ *
+ * Returns: TTT_CELL_X if X's win. TTT_CELL_O if O's
+ * win. TTT_CELL_EMPTY if no win. The game can then check the value
+ * of the return and declare the winner.
+ */
+
+ttt_cell_t ttt_board_is_won (ttt_board_t *board)
+{
+ int i;
+
+ /* Loop over rows and columns looking for a win. */
+ for (i = 0; i < 3; i++)
{
- board->cells[move] = 'X';
- return(1);
+ /* Check the current column */
+ if (board->cells[i] != TTT_CELL_EMPTY &&
+ board->cells[i] == board->cells[i + 3] &&
+ board->cells[i] == board->cells[i + 6])
+ {
+ return board->cells[i];
+ }
+
+ /* Check the current row */
+ if (board->cells[i * 3] != TTT_CELL_EMPTY &&
+ board->cells[i * 3] == board->cells[(i * 3) + 1] &&
+ board->cells[i * 3] == board->cells[(i * 3) + 2])
+ {
+ return board->cells[i * 3];
+ }
}
- else
+
+ if (board->cells[0] != TTT_CELL_EMPTY &&
+ board->cells[0] == board->cells[4] &&
+ board->cells[0] == board->cells[8])
{
- return(0);
+ return board->cells[0];
}
+
+ if (board->cells[2] != TTT_CELL_EMPTY &&
+ board->cells[2] == board->cells[4] &&
+ board->cells[2] == board->cells[6])
+ {
+ return board->cells[2];
+ }
+
+ return TTT_CELL_EMPTY;
}