/* * Assign a child-thread starting point within the maze. Return 1 if * successful, return 0 if not. For example, if some other thread * already is starting at the desired point, a second attempt to assign * that same point will fail. Just ABORT() if invalid starting point * given. */ int maze_solve_start_assign(struct maze *mp, int tid, int r, int c) { cell_t *cp; int i; struct maze_child *mcp = mp->msp->mcp; /* Die if the point lies outside of the maze. */ if (!maze_cell_exists(mp, r, c) || tid >= nthreads) ABORT(); /* * Return 0 if this point is already assigned to some other thread. * Or if some other point is already assigned to this thread, for * that matter. */ cp = maze_get_cell_addr(mp, r, c); if (*cp & VISITED || mcp[tid].startrow != -1) return 0; /* Assign the point. */ mcp[tid].startrow = r; mcp[tid].startcol = c; mcp[tid].visited[0].row = r; mcp[tid].visited[0].col = c; mcp[tid].vi = 1; *cp |= VISITED | tid; maze_set_cell_distance(mp, r, c, 1); return 1; }
/* Build a wall if appropriate. */ void maze_build_one_cell_wall(struct maze *mp, int wallrow, int wallcol, int prevrow, int prevcol, int currow, int curcol, int nextrow, int nextcol) { cell_t wallbit; cell_t *cp; /* If the candidate cell is either prev or next, no wall. */ if (wallrow == prevrow && wallcol == prevcol) return; if (wallrow == nextrow && wallcol == nextcol) return; /* If the wall cell actually exists, we need a wall. */ if (maze_cell_exists(mp, wallrow, wallcol)) { /* Wall in other cell. */ wallbit = maze_find_wallbit(wallrow, wallcol, currow, curcol); cp = maze_get_cell_addr(mp, wallrow, wallcol); *cp |= wallbit; /* Wall in current cell. */ wallbit = maze_find_wallbit(currow, curcol, wallrow, wallcol); cp = maze_get_cell_addr(mp, currow, curcol); *cp |= wallbit; } }
/* * Wall in the specified cell. This allows easy construction of * unsolvable mazes. Returns 1 on success, and 0 if the specified * cell was not in the maze. */ int maze_wall_in(struct maze *mp, int row, int col) { if (!maze_cell_exists(mp, row, col)) return 0; if (maze_cells_connected(mp, row, col, row - 1, col)) maze_build_one_cell_wall(mp, row - 1, col, row, col, row, col, row, col); if (maze_cells_connected(mp, row, col, row + 1, col)) maze_build_one_cell_wall(mp, row + 1, col, row, col, row, col, row, col); if (maze_cells_connected(mp, row, col, row, col - 1)) maze_build_one_cell_wall(mp, row, col - 1, row, col, row, col, row, col); if (maze_cells_connected(mp, row, col, row, col + 1)) maze_build_one_cell_wall(mp, row, col + 1, row, col, row, col, row, col); return 1; }
int main(int argc, char *argv[]) { unsigned long long dt; int i = 1; struct maze *mp; double q; int solved = 1; char *binin = NULL; char *binout = NULL; FILE *figfp = stdout; char *figout = NULL; int figupc = 300; int figupcgiven = 0; int figvisit = 0; int generate = 0; int rows = 41; int cols = 32; double straightfrac = 0.2; double segbends = 4; double revisit = 0.2; unsigned long seed = current_time(); int startrow = 0; int startcol = 0; int endrow = -1; int endcol = -1; int wallin = 0; int wallinrow; int wallincol; int solve = 1; int clear = 0; /* Parse arguments. */ while (i < argc) { if (strcmp(argv[i], "--input") == 0) { if (generate) usage(argv[0], "Conflict: --input and --generate\n"); if (i >= argc - 1) usage(argv[0], "--input requires path name\n"); binin = argv[++i]; } else if (strcmp(argv[i], "--output") == 0) { if (i >= argc - 1) usage(argv[0], "--output requires path name\n"); binout = argv[++i]; } else if (strcmp(argv[i], "--fig") == 0) { if (i >= argc - 1) usage(argv[0], "--fig requires path name\n"); figout = argv[++i]; figfp = fopen(figout, "w"); if (figfp == NULL) usage(argv[0], "--fig file unwriteable\n"); } else if (strcmp(argv[i], "--figupc") == 0) { if (i >= argc - 1) usage(argv[0], "--figupc requires fig units per cell\n"); figupc = strtol(argv[++i], NULL, 0); if (figupc <= 0) usage(argv[0], "--figupc must be non-negative\n"); figupcgiven = 1; } else if (strcmp(argv[i], "--figlinethickness") == 0) { if (i >= argc - 1) usage(argv[0], "--figlinethickness requires number\n"); line_thickness = strtol(argv[++i], NULL, 0); if (line_thickness <= 0) usage(argv[0], "--figlinethickness must be " "non-negative\n"); } else if (strcmp(argv[i], "--figvisit") == 0) { figvisit = 1; } else if (strcmp(argv[i], "--nofig") == 0) { if (figfp != stdout) usage(argv[0], "Conflict: --fig and --nofig\n"); figfp = NULL; } else if (strcmp(argv[i], "--generate") == 0) { generate = 1; if (binin) usage(argv[0], "Conflict: --generate and --input\n"); if (i < argc - 1 && argv[i + 1][0] != '-') { rows = strtol(argv[++i], NULL, 0); cols = rows; } if (i < argc - 1 && argv[i + 1][0] != '-') cols = strtol(argv[++i], NULL, 0); } else if (strcmp(argv[i], "--gen_sf") == 0) { if (i >= argc - 1) usage(argv[0], "--gen_sf requires straightfrac\n"); straightfrac = strtod(argv[++i], NULL); if (straightfrac <= 0.0) usage(argv[0], "--gen_sf requires straightfrac > 0"); } else if (strcmp(argv[i], "--gen_sb") == 0) { if (i >= argc - 1) usage(argv[0], "--gen_sb requires segbends\n"); segbends = strtod(argv[++i], NULL); if (segbends < 0.0) usage(argv[0], "--gen_sb requires segbends >= 0\n"); } else if (strcmp(argv[i], "--gen_rv") == 0) { if (i >= argc - 1) usage(argv[0], "--gen_rv requires revisit\n"); revisit = strtod(argv[++i], NULL); if (revisit < 0.0 || revisit > 1.0) usage(argv[0], "--gen_rv: 0 <= revisit <= 1\n"); } else if (strcmp(argv[i], "--seed") == 0) { if (i >= argc - 1) usage(argv[0], "--seed requires integer\n"); seed = strtol(argv[++i], NULL, 0); } else if (strcmp(argv[i], "--solve") == 0) { solve = 1; } else if (strcmp(argv[i], "--start") == 0) { if (i >= argc - 2) usage(argv[0], "--start requires position\n"); startrow = strtol(argv[++i], NULL, 0); startcol = strtol(argv[++i], NULL, 0); } else if (strcmp(argv[i], "--end") == 0) { if (i >= argc - 2) usage(argv[0], "--end requires position\n"); endrow = strtol(argv[++i], NULL, 0); endcol = strtol(argv[++i], NULL, 0); } else if (strcmp(argv[i], "--wall-in") == 0) { if (i >= argc - 2) usage(argv[0], "--wall-in requires position\n"); if (wallin) usage(argv[0], "Multiple --wall-in commands\n"); wallin = 1; wallinrow = strtol(argv[++i], NULL, 0); wallincol = strtol(argv[++i], NULL, 0); } else if (strcmp(argv[i], "--nosolve") == 0) { solve = 0; } else if (strcmp(argv[i], "--clear") == 0) { clear = 1; } else if (strcmp(argv[i], "--help") == 0) { usage(argv[0], ""); } else { int j = maze_solve_parse(i, argc, argv); if (i == j) usage(argv[0], "Unrecognized argument: %s\n", argv[i]); i = j - 1; } i++; } /* Get maze. */ srandom(seed); if (generate) { if (startrow < 0) startrow = maze_row_col_frac(rows, 1, -startrow); if (startcol < 0) startcol = maze_row_col_frac(cols, 1, -startcol); if (endrow < 0) endrow = maze_row_col_frac(rows, 1, -endrow); if (endcol < 0) endcol = maze_row_col_frac(cols, 1, -endcol); mp = maze_create(rows, cols, startrow, startcol, straightfrac, segbends, revisit); } else if (binin != NULL) { mp = maze_binary_in(binin); if (mp == NULL) usage(argv[0], "Bad --input file\n"); if (clear) maze_unvisit_all(mp); if (startrow < 0) startrow = maze_row_col_frac(mp->nrows, 1, -startrow); if (startcol < 0) startcol = maze_row_col_frac(mp->ncols, 1, -startcol); if (endrow < 0) endrow = maze_row_col_frac(mp->nrows, 1, -endrow); if (endcol < 0) endcol = maze_row_col_frac(mp->ncols, 1, -endcol); } else { usage(argv[0], "Must specify one of --input and --generate\n"); } if (startrow == endrow && startcol == endcol) usage(argv[0], "--start and --end both (%d, %d)\n", startrow, startcol); /* Wall-in the specified cell. */ if (wallin) { if (wallinrow < 0) wallinrow = maze_row_col_frac(mp->nrows, 1, -wallinrow); if (wallincol < 0) wallincol = maze_row_col_frac(mp->ncols, 1, -wallincol); if (!maze_wall_in(mp, wallinrow, wallincol)) usage(argv[0], "--wall-in %d %d must be within maze, " "limits: %d %d.\n", wallinrow, wallincol, mp->nrows, mp->ncols); } /* Solve maze. */ if (solve) { maze_unvisit_all(mp); /* Erase any prior solution. */ if (!maze_cell_exists(mp, startrow, startcol)) { fprintf(stderr, "Start position %d %d must be within maze: " "(0-%d, 0-%d)\n", startrow, startcol, mp->nrows - 1, mp->ncols - 1); exit(EXIT_FAILURE); } if (!maze_cell_exists(mp, endrow, endcol)) { fprintf(stderr, "End position %d %d must be within maze: " "(0-%d, 0-%d)\n", endrow, endcol, mp->nrows - 1, mp->ncols - 1); exit(EXIT_FAILURE); } q = maze_solve(mp, startrow, startcol, endrow, endcol, &dt); if (q == 0) { fprintf(stderr, "Maze has no solution\n"); solved = 0; } q = q / (double)(abs(endrow - startrow) + abs(endcol - startcol) + 1); fprintf(stderr, "Maze quality: %g dt = %g visits = %d/%d (%g%%)\n", q, ((double)dt) / (double)1000000, mp->vi, mp->nrows * mp->ncols, mp->vi * 100. / (double)(mp->nrows * mp->ncols)); } /* Output binary, if requested. */ if (binout != NULL) maze_binary_out(binout, mp); /* Output fig, if requested. */ if (figfp != NULL) { if (!figupcgiven) { /* Set up for US Letter. */ int fr = 300 * 41 / mp->nrows; int fc = 300 * 32 / mp->ncols; if (fr < fc) figupc = fr; else figupc = fc; } maze_to_fig(figfp, mp, figupc, !solved || figvisit); } return EXIT_SUCCESS; }
/* * Has the specified cell been visited? If it does not exist, that * counts as having been visited. */ int maze_cell_visited(struct maze *mp, int row, int col) { if (!maze_cell_exists(mp, row, col)) return 1; return !!(maze_get_cell(mp, row, col) & VISITED); }