152 lines
2.7 KiB
C
152 lines
2.7 KiB
C
/**
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* Sudoku board implementation
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*
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* Created by Gabriel Tofvesson
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "board.h"
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/**
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* Raises an error by printing it to stderr and stopping execution
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*/
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#define ERROR(reason) \
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{ \
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fprintf(stderr, "ERROR: %s\n", reason); \
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abort(); \
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}
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/**
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* Check if a given xy-pair is in bounds of a Sudoku board
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*/
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static inline bool
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is_in_bounds (board_pos x, board_pos y)
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{
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return x >= 0 &&
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x < 9 &&
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y >= 0 &&
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y < 9 ;
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}
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/**
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* Check if a given element value is within acceptable bounds
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*/
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static inline bool
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is_valid_value (element_value value)
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{
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return value >= 0 &&
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value < 9 ;
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}
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void
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board_init (struct board *board)
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{
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memset (board, 0, sizeof board->elements);
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board->complexity = 0;
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}
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void
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board_set (
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struct board *board,
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board_pos x,
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board_pos y,
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element_value value
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)
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{
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if (is_in_bounds (x, y) && is_valid_value (value))
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{
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struct board_element *elem = BOARD_ELEM (board, x, y);
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elem->has_value = true;
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elem->value = value;
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}
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else ERROR("Invalid parameters to function board_set()");
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}
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void
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board_mark (
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struct board *board,
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board_pos x,
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board_pos y,
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element_value value
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)
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{
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if (is_in_bounds (x, y) && is_valid_value (value))
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{
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struct board_element *elem = BOARD_ELEM (board, x, y);
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elem->potential |= 1 << value;
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}
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else ERROR("Invalid parameters to function board_mark()");
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}
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void
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board_unmark (
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struct board *board,
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board_pos x,
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board_pos y,
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element_value value
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)
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{
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if (is_in_bounds (x, y) && is_valid_value (value))
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{
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struct board_element *elem = BOARD_ELEM (board, x, y);
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/* Shift bit to correct place and then invert first 9 bits */
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elem->potential &= (1 << value) ^ 0x1FF;
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}
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else ERROR("Invalid parameters to function board_unmark()");
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}
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bool
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board_has_value (
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struct board *board,
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board_pos x,
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board_pos y
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)
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{
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if (is_in_bounds (x, y))
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{
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return BOARD_ELEM (board, x, y)->has_value;
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}
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else ERROR("Invalid parameters to function board_has_value()");
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}
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element_value
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board_get_value (
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struct board *board,
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board_pos x,
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board_pos y
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)
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{
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if (is_in_bounds (x, y))
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{
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return BOARD_ELEM (board, x, y)->value;
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}
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else ERROR("Invalid parameters to function board_get_value()");
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}
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bool
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board_is_marked (
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struct board *board,
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board_pos x,
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board_pos y,
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element_value value
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)
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{
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if (is_in_bounds (x, y) && is_valid_value (value))
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{
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return BOARD_ELEM (board, x, y)->potential & (1 << value);
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}
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else ERROR("Invalid parameters to function board_is_marked()");
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}
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