+/****************************************************************************
+ * Copyright 2018-2021,2022 Thomas E. Dickey *
+ * Copyright 1998-2013,2017 Free Software Foundation, Inc. *
+ * *
+ * Permission is hereby granted, free of charge, to any person obtaining a *
+ * copy of this software and associated documentation files (the *
+ * "Software"), to deal in the Software without restriction, including *
+ * without limitation the rights to use, copy, modify, merge, publish, *
+ * distribute, distribute with modifications, sublicense, and/or sell *
+ * copies of the Software, and to permit persons to whom the Software is *
+ * furnished to do so, subject to the following conditions: *
+ * *
+ * The above copyright notice and this permission notice shall be included *
+ * in all copies or substantial portions of the Software. *
+ * *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS *
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF *
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. *
+ * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, *
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR *
+ * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR *
+ * THE USE OR OTHER DEALINGS IN THE SOFTWARE. *
+ * *
+ * Except as contained in this notice, the name(s) of the above copyright *
+ * holders shall not be used in advertising or otherwise to promote the *
+ * sale, use or other dealings in this Software without prior written *
+ * authorization. *
+ ****************************************************************************/
/*
* Knight's Tour - a brain game
*
* Eric S. Raymond <esr@snark.thyrsus.com> July 22 1995. Mouse support
* added September 20th 1995.
*
- * $Id: knight.c,v 1.13 1997/01/19 00:55:17 tom Exp $
+ * $Id: knight.c,v 1.52 2022/12/04 00:40:11 tom Exp $
*/
#include <test.priv.h>
-#include <ctype.h>
-#include <signal.h>
-#include <string.h>
-
/* board size */
-#define BDEPTH 8
-#define BWIDTH 8
+#define YLIMIT 8
+#define XLIMIT 8
+#define MAXMOVES (ylimit * xlimit)
/* where to start the instructions */
-#define INSTRY 2
-#define INSTRX 35
+#define INSTRY 2
+#define INSTRX 35
/* corner of board */
-#define BOARDY 2
-#define BOARDX 0
+#define BOARDY 2
+#define BOARDX 0
/* notification line */
-#define NOTIFYY 21
+#define NOTIFYY 21
/* virtual color values */
#define TRAIL_COLOR 1
#define PLUS_COLOR 2
#define MINUS_COLOR 3
-#define CX(x) (2 + 4 * (x))
-#define CY(y) (1 + 2 * (y))
+#define CX(x) (2 + 4 * (x))
+#define CY(y) (1 + 2 * (y))
#define cellmove(y, x) wmove(boardwin, CY(y), CX(x))
#define CXINV(x) (((x) - 1) / 4)
#define CYINV(y) (((y) - 2) / 2)
-typedef struct
-{
- short x, y;
-}
-cell;
-
-static short board[BDEPTH][BWIDTH]; /* the squares */
-static int rw,col; /* current row and column */
-static int lastrow,lastcol; /* last location visited */
-static cell history[BDEPTH*BWIDTH]; /* choice history */
-static int movecount; /* count of moves so far */
-static WINDOW *boardwin; /* the board window */
-static WINDOW *helpwin; /* the help window */
-static WINDOW *msgwin; /* the message window */
-static chtype trail = '#'; /* trail character */
-static chtype plus = '+'; /* cursor hot-spot character */
-static chtype minus = '-'; /* possible-move character */
-static chtype oldch;
-
-static void init(void);
-static void play(void);
-static void dosquares(void);
-static void drawmove(char, int, int, int, int);
-static bool evalmove(int, int);
-static bool chkmoves(void);
-static bool chksqr(int, int);
-static int iabs(int);
-
-int main(
- int argc GCC_UNUSED,
- char *argv[] GCC_UNUSED)
-{
- init();
+typedef struct {
+ int x, y;
+} HISTORY;
- play();
+typedef int SQUARES[YLIMIT][XLIMIT];
- endwin();
- return EXIT_SUCCESS;
-}
+static WINDOW *boardwin; /* the board window */
+static WINDOW *helpwin; /* the help window */
+static WINDOW *msgwin; /* the message window */
+
+#if HAVE_USE_DEFAULT_COLORS
+static bool d_option;
+#endif
-static void init (void)
+static chtype minus = '-'; /* possible-move character */
+static chtype oldch;
+static chtype plus = '+'; /* cursor hot-spot character */
+static chtype trail = '#'; /* trail character */
+
+static int ylimit = YLIMIT;
+static int xlimit = XLIMIT;
+static int maxmoves = (YLIMIT * XLIMIT);
+
+static int count_tries; /* count of trials so far */
+static int test_test; /* FIXME */
+/* *INDENT-OFF* */
+static const struct {
+ int y;
+ int x;
+} offsets[] = {
+ { 2, 1 },
+ { 1, 2 },
+ { -1, 2 },
+ { -2, 1 },
+ { -2, -1 },
+ { -1, -2 },
+ { 1, -2 },
+ { 2, -1 },
+};
+#define MAX_OFFSET (unsigned)SIZEOF(offsets)
+/* *INDENT-ON* */
+
+static void
+init_program(void)
{
- srand ((unsigned)getpid());
- initscr ();
- cbreak (); /* immediate char return */
- noecho (); /* no immediate echo */
- boardwin = newwin(BDEPTH * 2 + 1, BWIDTH * 4 + 1, BOARDY, BOARDX);
+ setlocale(LC_ALL, "");
+
+ srand((unsigned) getpid());
+ initscr();
+ cbreak(); /* immediate char return */
+ noecho(); /* no immediate echo */
+
+ maxmoves = MAXMOVES;
+ boardwin = newwin(ylimit * 2 + 1, xlimit * 4 + 1, BOARDY, BOARDX);
helpwin = newwin(0, 0, INSTRY, INSTRX);
- msgwin = newwin(1, INSTRX-1, NOTIFYY, 0);
+ msgwin = newwin(1, INSTRX - 1, NOTIFYY, 0);
+
scrollok(msgwin, TRUE);
keypad(boardwin, TRUE);
- if (has_colors())
- {
+ if (has_colors()) {
int bg = COLOR_BLACK;
start_color();
-#ifdef NCURSES_VERSION
- if (use_default_colors() == OK)
+#if HAVE_USE_DEFAULT_COLORS
+ if (d_option && (use_default_colors() == OK))
bg = -1;
#endif
- (void) init_pair(TRAIL_COLOR, COLOR_CYAN, bg);
- (void) init_pair(PLUS_COLOR, COLOR_RED, bg);
- (void) init_pair(MINUS_COLOR, COLOR_GREEN, bg);
+ (void) init_pair(TRAIL_COLOR, (short) COLOR_CYAN, (short) bg);
+ (void) init_pair(PLUS_COLOR, (short) COLOR_RED, (short) bg);
+ (void) init_pair(MINUS_COLOR, (short) COLOR_GREEN, (short) bg);
- trail |= COLOR_PAIR(TRAIL_COLOR);
- plus |= COLOR_PAIR(PLUS_COLOR);
- minus |= COLOR_PAIR(MINUS_COLOR);
+ trail |= (chtype) COLOR_PAIR(TRAIL_COLOR);
+ plus |= (chtype) COLOR_PAIR(PLUS_COLOR);
+ minus |= (chtype) COLOR_PAIR(MINUS_COLOR);
}
-
#ifdef NCURSES_MOUSE_VERSION
- (void) mousemask(BUTTON1_CLICKED, (mmask_t *)NULL);
-#endif /* NCURSES_MOUSE_VERSION*/
+ (void) mousemask(BUTTON1_CLICKED, (mmask_t *) NULL);
+#endif /* NCURSES_MOUSE_VERSION */
+#if defined(PDCURSES)
+ mouse_set(BUTTON1_RELEASED);
+#endif
oldch = minus;
}
-static void help1(void)
+static void
+help1(void)
/* game explanation -- initial help screen */
{
- (void)waddstr(helpwin, "Knight's move is a solitaire puzzle. Your\n");
- (void)waddstr(helpwin, "objective is to visit each square of the \n");
- (void)waddstr(helpwin, "chessboard exactly once by making knight's\n");
- (void)waddstr(helpwin, "moves (one square right or left followed \n");
- (void)waddstr(helpwin, "by two squares up or down, or two squares \n");
- (void)waddstr(helpwin, "right or left followed by one square up or\n");
- (void)waddstr(helpwin, "down). You may start anywhere.\n\n");
-
- (void)waddstr(helpwin, "Use arrow keys to move the cursor around.\n");
- (void)waddstr(helpwin, "When you want to move your knight to the \n");
- (void)waddstr(helpwin, "cursor location, press <space> or Enter.\n");
- (void)waddstr(helpwin, "Illegal moves will be rejected with an \n");
- (void)waddstr(helpwin, "audible beep.\n\n");
- (void)waddstr(helpwin, "The program will detect if you solve the\n");
- (void)waddstr(helpwin, "puzzle; also inform you when you run out\n");
- (void)waddstr(helpwin, "of legal moves.\n\n");
-
- (void)mvwaddstr(helpwin, NOTIFYY-INSTRY, 0,
- "Press `?' to go to keystroke help.");
+ (void) waddstr(helpwin, "Knight's move is a solitaire puzzle. Your\n");
+ (void) waddstr(helpwin, "objective is to visit each square of the \n");
+ (void) waddstr(helpwin, "chessboard exactly once by making knight's\n");
+ (void) waddstr(helpwin, "moves (one square right or left followed \n");
+ (void) waddstr(helpwin, "by two squares up or down, or two squares \n");
+ (void) waddstr(helpwin, "right or left followed by one square up or\n");
+ (void) waddstr(helpwin, "down). You may start anywhere.\n\n");
+
+ (void) waddstr(helpwin, "Use arrow keys to move the cursor around.\n");
+ (void) waddstr(helpwin, "When you want to move your knight to the \n");
+ (void) waddstr(helpwin, "cursor location, press <space> or Enter.\n");
+ (void) waddstr(helpwin, "Illegal moves will be rejected with an \n");
+ (void) waddstr(helpwin, "audible beep.\n\n");
+ (void) waddstr(helpwin, "The program will detect if you solve the\n");
+ (void) waddstr(helpwin, "puzzle; also inform you when you run out\n");
+ (void) waddstr(helpwin, "of legal moves.\n\n");
+
+ MvWAddStr(helpwin, NOTIFYY - INSTRY, 0,
+ "Press `?' to go to keystroke help.");
}
-static void help2(void)
+static void
+help2(void)
/* keystroke help screen */
{
- (void)waddstr(helpwin, "Possible moves are shown with `-'.\n\n");
-
- (void)waddstr(helpwin, "You can move around with the arrow keys or\n");
- (void)waddstr(helpwin, "with the rogue/hack movement keys. Other\n");
- (void)waddstr(helpwin, "commands allow you to undo moves or redraw.\n");
- (void)waddstr(helpwin, "Your mouse may work; try left-button to\n");
- (void)waddstr(helpwin, "move to the square under the pointer.\n\n");
-
- (void)waddstr(helpwin, "x,q -- exit y k u 7 8 9\n");
- (void)waddstr(helpwin, "r -- redraw screen \\|/ \\|/ \n");
- (void)waddstr(helpwin, "u -- undo move h-+-l 4-+-6\n");
- (void)waddstr(helpwin, " /|\\ /|\\ \n");
- (void)waddstr(helpwin, " b j n 1 2 3\n");
-
- (void)waddstr(helpwin,"\nYou can place your knight on the selected\n");
- (void)waddstr(helpwin, "square with spacebar, Enter, or the keypad\n");
- (void)waddstr(helpwin, "center key. You can quit with `x' or `q'.\n");
-
- (void)mvwaddstr(helpwin, NOTIFYY-INSTRY, 0,
- "Press `?' to go to game explanation");
+ (void) waddstr(helpwin, "Possible moves are shown with `-'.\n\n");
+
+ (void) waddstr(helpwin, "You can move around with the arrow keys or\n");
+ (void) waddstr(helpwin, "with the rogue/hack movement keys. Other\n");
+ (void) waddstr(helpwin, "commands allow you to undo moves or redraw.\n");
+ (void) waddstr(helpwin, "Your mouse may work; try left-button to\n");
+ (void) waddstr(helpwin, "move to the square under the pointer.\n\n");
+
+ (void) waddstr(helpwin, "x,q -- exit y k u 7 8 9\n");
+ (void) waddstr(helpwin, "r -- redraw screen \\|/ \\|/ \n");
+ (void) waddstr(helpwin, "bksp -- undo move h-+-l 4-+-6\n");
+ (void) waddstr(helpwin, "a -- autojump /|\\ /|\\ \n");
+ if (ylimit <= 6) {
+ (void) waddstr(helpwin, "R -- solve (slow) b j n 1 2 3\n");
+ } else {
+ (void) waddstr(helpwin, " b j n 1 2 3\n");
+ }
+
+ (void) waddstr(helpwin, "\nYou can place your knight on the selected\n");
+ (void) waddstr(helpwin, "square with spacebar, Enter, or the keypad\n");
+ (void) waddstr(helpwin, "center key. Use F/B to review the path.\n");
+
+ MvWAddStr(helpwin, NOTIFYY - INSTRY, 0,
+ "Press `?' to go to game explanation");
+}
+
+static void
+show_help(bool * keyhelp)
+{
+ werase(helpwin);
+ if (*keyhelp) {
+ help1();
+ *keyhelp = FALSE;
+ } else {
+ help2();
+ *keyhelp = TRUE;
+ }
+ wrefresh(helpwin);
}
-static void play (void)
-/* play the game */
+static inline bool
+isValidYX(int y, int x)
{
- bool keyhelp; /* TRUE if keystroke help is up */
- int c, ny = 0, nx = 0;
- int i, j, count;
+ return (y >= 0 && y < ylimit && x >= 0 && x < xlimit) ? TRUE : FALSE;
+}
- do {
- /* clear screen and draw board */
- werase(boardwin);
- werase(helpwin);
- werase(msgwin);
- dosquares();
- help1();
- wnoutrefresh(stdscr);
- wnoutrefresh(helpwin);
- wnoutrefresh(msgwin);
- wnoutrefresh(boardwin);
- doupdate();
-
- for (i = 0; i < BDEPTH; i++)
- for (j = 0; j < BWIDTH; j++)
- {
- board[i][j] = FALSE;
- cellmove(i, j);
- waddch(boardwin, minus);
- }
- memset(history, '\0', sizeof(history));
- history[0].y = history[0].x = -1;
- lastrow = lastcol = -2;
- movecount = 1;
- keyhelp = FALSE;
-
- for (;;)
- {
- if (rw != lastrow || col != lastcol)
- {
- if (lastrow >= 0 && lastcol >= 0)
- {
- cellmove(lastrow, lastcol);
- if (board[lastrow][lastcol])
- waddch(boardwin, trail);
- else
- waddch(boardwin, oldch);
- }
-
- cellmove(rw, col);
- oldch = winch(boardwin);
-
- lastrow = rw;
- lastcol= col;
- }
- cellmove(rw, col);
- waddch(boardwin, plus);
- cellmove(rw, col);
-
- wrefresh(msgwin);
-
- c = wgetch(boardwin);
-
- werase(msgwin);
-
- switch (c)
- {
- case 'k': case '8':
- case KEY_UP:
- ny = rw+BDEPTH-1; nx = col;
- break;
- case 'j': case '2':
- case KEY_DOWN:
- ny = rw+1; nx = col;
- break;
- case 'h': case '4':
- case KEY_LEFT:
- ny = rw; nx = col+BWIDTH-1;
- break;
- case 'l': case '6':
- case KEY_RIGHT:
- ny = rw; nx = col+1;
- break;
- case 'y': case '7':
- case KEY_A1:
- ny = rw+BDEPTH-1; nx = col+BWIDTH-1;
- break;
- case 'b': case '1':
- case KEY_C1:
- ny = rw+1; nx = col+BWIDTH-1;
- break;
- case 'u': case '9':
- case KEY_A3:
- ny = rw+BDEPTH-1; nx = col+1;
- break;
- case 'n': case '3':
- case KEY_C3:
- ny = rw+1; nx = col+1;
- break;
+static inline bool
+isUnusedYX(SQUARES squares, int y, int x)
+{
+ return (isValidYX(y, x) && (!squares[y][x]) ? TRUE : FALSE);
+}
-#ifdef NCURSES_MOUSE_VERSION
- case KEY_MOUSE:
- {
- MEVENT myevent;
-
- getmouse(&myevent);
- if (myevent.y >= CY(0) && myevent.y <= CY(BDEPTH)
- && myevent.x >= CX(0) && myevent.x <= CX(BWIDTH))
- {
- nx = CXINV(myevent.x);
- ny = CYINV(myevent.y);
- ungetch('\n');
- break;
- }
- else
- {
- beep();
- continue;
- }
- }
-#endif /* NCURSES_MOUSE_VERSION */
+static bool
+boardIsFilled(SQUARES squares, int y, int x)
+{
+ unsigned n;
- case KEY_B2:
- case '\n':
- case ' ':
- if (evalmove(rw, col))
- {
- drawmove(trail,
- history[movecount-1].y, history[movecount-1].x,
- rw, col);
- history[movecount].y = rw;
- history[movecount].x = col;
- movecount++;
-
- if (!chkmoves())
- goto dropout;
- }
- else
- beep();
- break;
-
- case KEY_REDO:
- case '\f':
- case 'r':
- clearok(curscr, TRUE);
- wnoutrefresh(stdscr);
- wnoutrefresh(boardwin);
- wnoutrefresh(msgwin);
- wnoutrefresh(helpwin);
- doupdate();
- break;
-
- case KEY_UNDO:
- case KEY_BACKSPACE:
- case '\b':
- if (movecount == 1)
- {
- ny = lastrow;
- nx = lastcol;
- waddstr(msgwin, "\nNo previous move.");
- beep();
- }
- else
- {
- int oldy = history[movecount-1].y;
- int oldx = history[movecount-1].x;
-
- board[oldy][oldx] = FALSE;
- --movecount;
- ny = history[movecount-1].y;
- nx = history[movecount-1].x;
- drawmove(' ', oldy, oldx, ny, nx);
-
- /* avoid problems if we just changed the current cell */
- cellmove(lastrow, lastcol);
- oldch = winch(boardwin);
- }
- break;
-
- case 'q':
- case 'x':
- goto dropout;
-
- case '?':
- werase(helpwin);
- if (keyhelp)
- {
- help1();
- keyhelp = FALSE;
- }
- else
- {
- help2();
- keyhelp = TRUE;
- }
- wrefresh(helpwin);
- break;
-
- default:
- beep();
- break;
- }
-
- col = nx % BWIDTH;
- rw = ny % BDEPTH;
- }
-
- dropout:
- count = 0;
- for (i = 0; i < BDEPTH; i++)
- for (j = 0; j < BWIDTH; j++)
- if (board[i][j] != 0)
- count += 1;
- if (count == (BWIDTH * BDEPTH))
- wprintw(msgwin, "\nYou won. Care to try again? ");
- else
- wprintw(msgwin, "\n%d squares filled. Try again? ", count);
- } while
- (tolower(wgetch(msgwin)) == 'y');
+ for (n = 0; n < MAX_OFFSET; n++) {
+ if (isUnusedYX(squares, y + offsets[n].y, x + offsets[n].x)) {
+ return FALSE;
+ }
+ }
+ return TRUE;
}
-static void dosquares (void)
+static void
+drawBoard(void)
{
int i, j;
- mvaddstr(0, 20, "KNIGHT'S MOVE -- a logical solitaire");
+ MvAddStr(0, 20, "KNIGHT'S MOVE -- a logical solitaire");
- move(BOARDY,BOARDX);
+ move(BOARDY, BOARDX);
waddch(boardwin, ACS_ULCORNER);
- for (j = 0; j < 7; j++)
- {
+ for (j = 0; j < (ylimit - 1); j++) {
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_URCORNER);
- for (i = 1; i < BDEPTH; i++)
- {
+ for (i = 1; i < ylimit; i++) {
move(BOARDY + i * 2 - 1, BOARDX);
- waddch(boardwin, ACS_VLINE);
- for (j = 0; j < BWIDTH; j++)
- {
+ waddch(boardwin, ACS_VLINE);
+ for (j = 0; j < xlimit; j++) {
waddch(boardwin, ' ');
waddch(boardwin, ' ');
waddch(boardwin, ' ');
waddch(boardwin, ACS_VLINE);
}
move(BOARDY + i * 2, BOARDX);
- waddch(boardwin, ACS_LTEE);
- for (j = 0; j < BWIDTH - 1; j++)
- {
+ waddch(boardwin, ACS_LTEE);
+ for (j = 0; j < xlimit - 1; j++) {
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
move(BOARDY + i * 2 - 1, BOARDX);
waddch(boardwin, ACS_VLINE);
- for (j = 0; j < BWIDTH; j++)
- {
+ for (j = 0; j < xlimit; j++) {
waddch(boardwin, ' ');
waddch(boardwin, ' ');
waddch(boardwin, ' ');
move(BOARDY + i * 2, BOARDX);
waddch(boardwin, ACS_LLCORNER);
- for (j = 0; j < BWIDTH - 1; j++)
- {
+ for (j = 0; j < xlimit - 1; j++) {
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_LRCORNER);
}
-static void mark_possibles(int prow, int pcol, chtype mark)
+static void
+mark_possibles(SQUARES squares, int y, int x, chtype mark)
+{
+ unsigned n;
+
+ for (n = 0; n < MAX_OFFSET; n++) {
+ if (isUnusedYX(squares, y + offsets[n].y, x + offsets[n].x)) {
+ cellmove(y + offsets[n].y, x + offsets[n].x);
+ waddch(boardwin, mark);
+ }
+ }
+}
+
+static bool
+find_next_move(SQUARES squares, HISTORY * doneData, int doneSize, int *y, int *x)
+{
+ bool result = FALSE;
+
+ if (doneSize > 1) {
+ unsigned j;
+ int oldy = doneData[doneSize - 1].y;
+ int oldx = doneData[doneSize - 1].x;
+ int found = -1;
+ int first = -1;
+ int next = -1;
+
+ for (j = 0; j < MAX_OFFSET * 2; j++) {
+ unsigned k = j % MAX_OFFSET;
+ int newy = oldy + offsets[k].y;
+ int newx = oldx + offsets[k].x;
+ if (isUnusedYX(squares, newy, newx)) {
+ if (first < 0)
+ first = (int) k;
+ if (newy == *y
+ && newx == *x) {
+ found = (int) k;
+ } else if (found >= 0) {
+ next = (int) k;
+ break;
+ }
+ }
+ }
+ if (found < 0)
+ next = first;
+ if (next >= 0) {
+ *y = oldy + offsets[next].y;
+ *x = oldx + offsets[next].x;
+ }
+ result = TRUE;
+ }
+ return result;
+}
+
+static void
+count_next_moves(SQUARES squares, int count_moves, int y, int x)
+{
+ int count = 0;
+ unsigned j;
+
+ wprintw(msgwin, "\nMove %d", count_moves);
+ for (j = 0; j < MAX_OFFSET; j++) {
+ int newy = y + offsets[j].y;
+ int newx = x + offsets[j].x;
+ if (isUnusedYX(squares, newy, newx)) {
+ ++count;
+ }
+ }
+ wprintw(msgwin, ", gives %d choices", count);
+ wclrtoeol(msgwin);
+}
+
+static void
+unmarkcell(int row, int column)
+{
+ cellmove(row, column);
+ waddch(boardwin, '\b');
+ waddch(boardwin, ' ');
+ waddch(boardwin, minus);
+ waddch(boardwin, ' ');
+}
+
+static void
+markcell(chtype tchar, int row, int column)
{
- if (chksqr(prow+2,pcol+1)){cellmove(prow+2,pcol+1);waddch(boardwin,mark);};
- if (chksqr(prow+2,pcol-1)){cellmove(prow+2,pcol-1);waddch(boardwin,mark);};
- if (chksqr(prow-2,pcol+1)){cellmove(prow-2,pcol+1);waddch(boardwin,mark);};
- if (chksqr(prow-2,pcol-1)){cellmove(prow-2,pcol-1);waddch(boardwin,mark);};
- if (chksqr(prow+1,pcol+2)){cellmove(prow+1,pcol+2);waddch(boardwin,mark);};
- if (chksqr(prow+1,pcol-2)){cellmove(prow+1,pcol-2);waddch(boardwin,mark);};
- if (chksqr(prow-1,pcol+2)){cellmove(prow-1,pcol+2);waddch(boardwin,mark);};
- if (chksqr(prow-1,pcol-2)){cellmove(prow-1,pcol-2);waddch(boardwin,mark);};
+ cellmove(row, column);
+ waddch(boardwin, '\b');
+ waddch(boardwin, tchar);
+ waddch(boardwin, tchar);
+ waddch(boardwin, tchar);
}
-static void drawmove(char tchar, int oldy, int oldx, int row, int column)
+static void
+drawMove(SQUARES squares, int count_moves, chtype tchar, int oldy, int oldx, int
+ row, int column)
/* place the stars, update board & currents */
{
- if (movecount <= 1)
- {
+ if (count_moves <= 1) {
int i, j;
- for (i = 0; i < BDEPTH; i++)
- for (j = 0; j < BWIDTH; j++)
- {
- cellmove(i, j);
- if (winch(boardwin) == minus)
- waddch(boardwin, movecount ? ' ' : minus);
+ for (i = 0; i < ylimit; i++) {
+ for (j = 0; j < xlimit; j++) {
+ if (count_moves == 0) {
+ unmarkcell(i, j);
+ } else {
+ cellmove(i, j);
+ if (winch(boardwin) == minus)
+ waddch(boardwin, ' ');
+ }
}
- }
- else
- {
- cellmove(oldy, oldx);
- waddch(boardwin, '\b');
- waddch(boardwin, tchar);
- waddch(boardwin, tchar);
- waddch(boardwin, tchar);
- mark_possibles(oldy, oldx, ' ');
+ }
+ } else {
+ markcell(tchar, oldy, oldx);
+ mark_possibles(squares, oldy, oldx, ' ');
}
- if (row != -1 && column != -1)
- {
- cellmove(row, column);
- waddch(boardwin, '\b');
- waddch(boardwin, trail);
- waddch(boardwin, trail);
- waddch(boardwin, trail);
- mark_possibles(row, column, minus);
- board[row][column] = TRUE;
+ if (row >= 0 && column >= 0) {
+ markcell(trail, row, column);
+ mark_possibles(squares, row, column, minus);
+ squares[row][column] = TRUE;
}
- wprintw(msgwin, "\nMove %d", movecount);
+ wprintw(msgwin, "\nMove %d", count_moves);
+ if (count_tries != count_moves)
+ wprintw(msgwin, " (%d tries)", count_tries);
+ wclrtoeol(msgwin);
}
-static bool evalmove(int row, int column)
-/* evaluate move */
+static int
+iabs(int num)
{
- if (movecount == 1)
- return(TRUE);
- else if (board[row][column] == TRUE)
- {
- waddstr(msgwin, "\nYou've already been there.");
- return(FALSE);
- }
+ if (num < 0)
+ return (-num);
else
- {
- int rdif = iabs(row - history[movecount-1].y);
- int cdif = iabs(column - history[movecount-1].x);
+ return (num);
+}
- if (!((rdif == 1) && (cdif == 2)) && !((rdif == 2) && (cdif == 1)))
- {
+static bool
+evaluate_move(SQUARES squares, HISTORY * doneData, int doneSize, int row, int column)
+{
+ if (doneSize <= 1)
+ return (TRUE);
+ else if (squares[row][column] == TRUE) {
+ waddstr(msgwin, "\nYou've already been there.");
+ return (FALSE);
+ } else {
+ int rdif = iabs(row - doneData[doneSize - 1].y);
+ int cdif = iabs(column - doneData[doneSize - 1].x);
+
+ if (!((rdif == 1) && (cdif == 2)) && !((rdif == 2) && (cdif == 1))) {
waddstr(msgwin, "\nThat's not a legal knight's move.");
- return(FALSE);
+ return (FALSE);
+ }
+ }
+
+ return (TRUE);
+}
+
+static int
+completed(SQUARES squares)
+{
+ int i, j, count = 0;
+
+ for (i = 0; i < ylimit; i++) {
+ for (j = 0; j < xlimit; j++) {
+ if (squares[i][j] != 0) {
+ count += 1;
+ }
+ }
+ }
+ return ((count == maxmoves) ? -1 : count);
+}
+
+static void
+no_previous_move(void)
+{
+ waddstr(msgwin, "\nNo previous move.");
+ beep();
+}
+
+/* Recursively try all possible moves, starting from (y,x) */
+static int
+recurBack(SQUARES squares, int y, int x, int total)
+{
+ int longest = total;
+ int best_x = x;
+ int best_y = y;
+ int result;
+
+ if (total < maxmoves) {
+ unsigned k;
+
+ for (k = 0; k < MAX_OFFSET; k++) {
+ int try_x = x + offsets[k].x;
+ int try_y = y + offsets[k].y;
+ if (isUnusedYX(squares, try_y, try_x)) {
+ ++test_test;
+ squares[try_y][try_x] = total + 1;
+ result = recurBack(squares, try_y, try_x, total + 1);
+ if (result > longest) {
+ longest = result;
+ best_x = try_x;
+ best_y = try_y;
+ }
+ if (result >= maxmoves)
+ break;
+ squares[try_y][try_x] = 0; /* allow retry... */
+ }
}
}
- return(TRUE);
+ result = total;
+ if (longest > total) {
+ result = longest;
+ squares[best_y][best_x] = total + 1;
+ (void) recurBack(squares, best_y, best_x, total + 1);
+ if (result < maxmoves)
+ squares[best_y][best_x] = 0;
+ }
+
+ return result;
+}
+
+/*
+ * Solve the Knight Tour problem using backtracking, returning the length of
+ * the resulting solution. If this is invoked from a point where the remaining
+ * choices cannot complete the tour, the result will fall short.
+ */
+static int
+useBacktracking(SQUARES result, HISTORY * doneData, int doneSize)
+{
+ int y = 0, x = 0, n;
+ SQUARES squares;
+ int total;
+ int actual = doneSize - 1;
+
+ memset(squares, 0, sizeof(squares));
+ for (n = 1; n <= actual; ++n) {
+ y = doneData[n].y;
+ x = doneData[n].x;
+ squares[y][x] = n;
+ }
+
+ total = recurBack(squares, y, x, actual);
+ if (total > actual) {
+ for (y = 0; y < ylimit; ++y) {
+ for (x = 0; x < xlimit; ++x) {
+ result[y][x] = squares[y][x];
+ if ((n = squares[y][x]) != 0) {
+ doneData[n].y = y;
+ doneData[n].x = x;
+ }
+ }
+ }
+ }
+ return total;
}
-static bool chkmoves (void)
-/* check to see if valid moves are available */
+static int
+reviewHistory(HISTORY * history, int count_moves, int review, int *ny, int *nx)
{
- if (chksqr(rw+2,col+1)) return(TRUE);
- if (chksqr(rw+2,col-1)) return(TRUE);
- if (chksqr(rw-2,col+1)) return(TRUE);
- if (chksqr(rw-2,col-1)) return(TRUE);
- if (chksqr(rw+1,col+2)) return(TRUE);
- if (chksqr(rw+1,col-2)) return(TRUE);
- if (chksqr(rw-1,col+2)) return(TRUE);
- if (chksqr(rw-1,col-2)) return(TRUE);
- return (FALSE);
+ if (review < 0) {
+ beep();
+ review = 0;
+ } else if (review > count_moves - 2) {
+ beep();
+ review = count_moves - 2;
+ } else {
+ *ny = history[count_moves - review - 1].y;
+ *nx = history[count_moves - review - 1].x;
+ wprintw(msgwin, "\nReview %d:%d.", count_moves - review - 1,
+ count_moves - 1);
+ wrefresh(msgwin);
+ }
+ return review;
}
-static int iabs(int num)
+static void
+play(void)
+/* play the game */
{
- if (num < 0) return (-num);
- else return (num);
+ bool keyhelp; /* TRUE if keystroke help is up */
+ int i, j, count;
+ int lastcol; /* last location visited */
+ int lastrow;
+ int ny = 0, nx = 0;
+ int review = 0; /* review history */
+ int test_size;
+ int rw = 0, col = 0; /* current row and column */
+
+ do {
+ SQUARES squares;
+ HISTORY history[(YLIMIT * XLIMIT) + 1];
+ int count_moves = 0; /* count of moves so far */
+
+ /* clear screen and draw board */
+ werase(boardwin);
+ werase(helpwin);
+ werase(msgwin);
+ drawBoard();
+ help1();
+ wnoutrefresh(stdscr);
+ wnoutrefresh(helpwin);
+ wnoutrefresh(msgwin);
+ wnoutrefresh(boardwin);
+ doupdate();
+
+ for (i = 0; i < ylimit; i++) {
+ for (j = 0; j < xlimit; j++) {
+ unmarkcell(i, j);
+ }
+ }
+ memset(squares, 0, sizeof(squares));
+ memset(history, 0, sizeof(history));
+ history[0].y = history[0].x = -1;
+ history[1].y = history[1].x = -1;
+ lastrow = lastcol = -2;
+ count_moves = 1;
+ count_tries = 1;
+ keyhelp = FALSE;
+ show_help(&keyhelp);
+
+ for (;;) {
+ if (rw != lastrow || col != lastcol) {
+ if (lastrow >= 0 && lastcol >= 0) {
+ cellmove(lastrow, lastcol);
+ if (squares[lastrow][lastcol])
+ waddch(boardwin, trail);
+ else
+ waddch(boardwin, oldch);
+ }
+
+ cellmove(rw, col);
+ oldch = winch(boardwin);
+
+ lastrow = rw;
+ lastcol = col;
+ }
+ cellmove(rw, col);
+ waddch(boardwin, plus);
+ cellmove(rw, col);
+
+ wrefresh(msgwin);
+
+ switch (wgetch(boardwin)) {
+ case 'k':
+ case '8':
+ case KEY_UP:
+ ny = rw + ylimit - 1;
+ nx = col;
+ break;
+ case 'j':
+ case '2':
+ case KEY_DOWN:
+ ny = rw + 1;
+ nx = col;
+ break;
+ case 'h':
+ case '4':
+ case KEY_LEFT:
+ ny = rw;
+ nx = col + xlimit - 1;
+ break;
+ case 'l':
+ case '6':
+ case KEY_RIGHT:
+ ny = rw;
+ nx = col + 1;
+ break;
+ case 'y':
+ case '7':
+ case KEY_A1:
+ ny = rw + ylimit - 1;
+ nx = col + xlimit - 1;
+ break;
+ case 'b':
+ case '1':
+ case KEY_C1:
+ ny = rw + 1;
+ nx = col + xlimit - 1;
+ break;
+ case 'u':
+ case '9':
+ case KEY_A3:
+ ny = rw + ylimit - 1;
+ nx = col + 1;
+ break;
+ case 'n':
+ case '3':
+ case KEY_C3:
+ ny = rw + 1;
+ nx = col + 1;
+ break;
+
+#ifdef KEY_MOUSE
+ case KEY_MOUSE:
+#ifdef NCURSES_MOUSE_VERSION
+ {
+ MEVENT myevent;
+
+ getmouse(&myevent);
+ if (myevent.y >= CY(0) && myevent.y <= CY(ylimit)
+ && myevent.x >= CX(0) && myevent.x <= CX(xlimit)) {
+ nx = CXINV(myevent.x);
+ ny = CYINV(myevent.y);
+ ungetch('\n');
+ break;
+ } else {
+ beep();
+ continue;
+ }
+ }
+#endif /* NCURSES_MOUSE_VERSION */
+#ifdef PDCURSES
+ {
+ int test_y, test_x;
+ request_mouse_pos();
+ test_y = MOUSE_Y_POS + 0;
+ test_x = MOUSE_X_POS + 1;
+ if (test_y >= CY(0) && test_y <= CY(ylimit)
+ && test_x >= CX(0) && test_x <= CX(xlimit)) {
+ ny = CYINV(test_y);
+ nx = CXINV(test_x);
+ wmove(helpwin, 0, 0);
+ wrefresh(helpwin);
+ ungetch('\n');
+ }
+ break;
+ }
+#endif /* PDCURSES */
+#endif /* KEY_MOUSE */
+
+ case KEY_B2:
+ case '\n':
+ case ' ':
+ review = 0;
+ if (evaluate_move(squares, history, count_moves, rw, col)) {
+ drawMove(squares,
+ count_moves,
+ trail,
+ history[count_moves - 1].y,
+ history[count_moves - 1].x,
+ rw, col);
+ history[count_moves].y = (short) rw;
+ history[count_moves].x = (short) col;
+ count_moves++;
+ count_tries++;
+
+ if (boardIsFilled(squares, rw, col)) {
+ if (completed(squares) < 0) {
+ waddstr(msgwin, "\nYou won.");
+ } else {
+ waddstr(msgwin,
+ "\nNo further moves are possible.");
+ }
+ }
+ } else {
+ beep();
+ }
+ break;
+
+ case KEY_UNDO:
+ case KEY_BACKSPACE:
+ case '\b':
+ review = 0;
+ if (count_moves <= 0) {
+ no_previous_move();
+ } else if (count_moves <= 1) {
+ ny = history[count_moves].y;
+ nx = history[count_moves].x;
+ if (nx < 0 || ny < 0) {
+ ny = (lastrow >= 0) ? lastrow : 0;
+ nx = (lastcol >= 0) ? lastcol : 0;
+ }
+ count_moves = 0;
+ squares[ny][nx] = FALSE;
+ oldch = minus;
+ drawMove(squares, count_moves, ' ', ny, nx, -1, -1);
+ count_moves = 1;
+ count_tries = 1;
+ no_previous_move();
+ } else {
+ int oldy = history[count_moves - 1].y;
+ int oldx = history[count_moves - 1].x;
+
+ if (!squares[rw][col]) {
+ cellmove(rw, col);
+ waddch(boardwin, ' ');
+ }
+
+ squares[oldy][oldx] = FALSE;
+ --count_moves;
+ ny = history[count_moves - 1].y;
+ nx = history[count_moves - 1].x;
+ if (nx < 0 || ny < 0) {
+ ny = oldy;
+ nx = oldx;
+ }
+ drawMove(squares, count_moves, ' ', oldy, oldx, ny, nx);
+
+ /* avoid problems if we just changed the current cell */
+ cellmove(lastrow, lastcol);
+ oldch = winch(boardwin);
+ }
+ break;
+
+ case 'a':
+ nx = col;
+ ny = rw;
+ if (find_next_move(squares, history, count_moves, &ny, &nx))
+ count_next_moves(squares, count_moves, ny, nx);
+ else
+ beep();
+ break;
+
+ case 'F':
+ review = reviewHistory(history, count_moves, review - 1,
+ &ny, &nx);
+ break;
+
+ case 'B':
+ review = reviewHistory(history, count_moves, review + 1,
+ &ny, &nx);
+ break;
+
+ case 'R':
+ if (ylimit <= 6) {
+ wprintw(msgwin, "\nworking...");
+ wrefresh(msgwin);
+ test_test = 0;
+ test_size = useBacktracking(squares, history, count_moves);
+ wprintw(msgwin, "\nOk %d:%d (%d tests)",
+ test_size, maxmoves, test_test);
+ review = 0;
+ while (count_moves <= test_size) {
+ markcell(trail,
+ ny = history[count_moves].y,
+ nx = history[count_moves].x);
+ count_moves++;
+ }
+ } else {
+ wprintw(msgwin, "\nBoard is too large.");
+ }
+ wrefresh(msgwin);
+ break;
+
+#if HAVE_CURSCR
+ case KEY_REDO:
+ case '\f':
+ case 'r':
+ clearok(curscr, TRUE);
+ wnoutrefresh(stdscr);
+ wnoutrefresh(boardwin);
+ wnoutrefresh(msgwin);
+ wnoutrefresh(helpwin);
+ doupdate();
+ break;
+#endif
+
+ case 'q':
+ case 'x':
+ goto dropout;
+
+ case HELP_KEY_1:
+ show_help(&keyhelp);
+ break;
+
+ default:
+ beep();
+ break;
+ }
+
+ col = nx % xlimit;
+ rw = ny % ylimit;
+ }
+
+ dropout:
+ if ((count = completed(squares)) < 0)
+ wprintw(msgwin, "\nYou won. Care to try again? ");
+ else
+ wprintw(msgwin, "\n%d squares filled. Try again? ", count);
+ wclrtoeol(msgwin);
+ } while
+ (tolower(wgetch(msgwin)) == 'y');
}
-static bool chksqr (int r1, int c1)
+static void
+usage(int ok)
{
- if ((r1 < 0) || (r1 > BDEPTH - 1))
- return(FALSE);
- if ((c1 < 0) || (c1 > BWIDTH - 1))
- return(FALSE);
- return (!board[r1][c1]);
+ static const char *msg[] =
+ {
+ "Usage: knight [options]"
+ ,""
+ ,USAGE_COMMON
+ ,"Options:"
+#if HAVE_USE_DEFAULT_COLORS
+ ," -d invoke use_default_colors"
+#endif
+ ," -n NUM set board-size to NUM*NUM (default 8x8)"
+ };
+ size_t n;
+
+ for (n = 0; n < SIZEOF(msg); n++)
+ fprintf(stderr, "%s\n", msg[n]);
+
+ ExitProgram(ok ? EXIT_SUCCESS : EXIT_FAILURE);
}
+/* *INDENT-OFF* */
+VERSION_COMMON()
+/* *INDENT-ON* */
-/* knight.c ends here */
+int
+main(int argc, char *argv[])
+{
+ int ch;
+
+ while ((ch = getopt(argc, argv, OPTS_COMMON "dn:")) != -1) {
+ switch (ch) {
+#if HAVE_USE_DEFAULT_COLORS
+ case 'd':
+ d_option = TRUE;
+ break;
+#endif
+ case 'n':
+ ch = atoi(optarg);
+ if (ch < 3 || ch > 8) {
+ fprintf(stderr, "board size %d is outside [3..8]\n", ch);
+ usage(FALSE);
+ }
+ xlimit = ylimit = ch;
+ break;
+ case OPTS_VERSION:
+ show_version(argv);
+ ExitProgram(EXIT_SUCCESS);
+ default:
+ usage(ch == OPTS_USAGE);
+ /* NOTREACHED */
+ }
+ }
+ if (optind < argc)
+ usage(FALSE);
+
+ init_program();
+
+ play();
+
+ endwin();
+ ExitProgram(EXIT_SUCCESS);
+}