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/*
* Knight's Tour - a brain game
*
* The original of this game was anonymous. It had an unbelievably bogus
* interface, you actually had to enter square coordinates! Redesign by
* Eric S. Raymond <esr@snark.thyrsus.com> July 22 1995. Mouse support
* added September 20th 1995.
*
* $Id: knight.c,v 1.26 2002/10/19 22:11:24 tom Exp $
*/
#include <test.priv.h>
/* board size */
#define BDEPTH 8
#define BWIDTH 8
/* where to start the instructions */
#define INSTRY 2
#define INSTRX 35
/* corner of board */
#define BOARDY 2
#define BOARDX 0
/* notification line */
#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 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 WINDOW *boardwin; /* the board window */
static WINDOW *helpwin; /* the help window */
static WINDOW *msgwin; /* the message window */
static cell history[BDEPTH * BWIDTH + 1]; /* choice history */
static chtype minus = '-'; /* possible-move character */
static chtype oldch;
static chtype plus = '+'; /* cursor hot-spot character */
static chtype trail = '#'; /* trail character */
static int movecount; /* count of moves so far */
static int trialcount; /* count of trials so far */
static short board[BDEPTH][BWIDTH]; /* the squares */
/* *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 },
};
/* *INDENT-ON* */
static void
init_program(void)
{
setlocale(LC_ALL, "");
srand((unsigned) getpid());
initscr();
cbreak(); /* immediate char return */
noecho(); /* no immediate echo */
boardwin = newwin(BDEPTH * 2 + 1, BWIDTH * 4 + 1, BOARDY, BOARDX);
helpwin = newwin(0, 0, INSTRY, INSTRX);
msgwin = newwin(1, INSTRX - 1, NOTIFYY, 0);
scrollok(msgwin, TRUE);
keypad(boardwin, TRUE);
if (has_colors()) {
int bg = COLOR_BLACK;
start_color();
#if HAVE_USE_DEFAULT_COLORS
if (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);
trail |= COLOR_PAIR(TRAIL_COLOR);
plus |= COLOR_PAIR(PLUS_COLOR);
minus |= COLOR_PAIR(MINUS_COLOR);
}
#ifdef NCURSES_MOUSE_VERSION
(void) mousemask(BUTTON1_CLICKED, (mmask_t *) NULL);
#endif /* NCURSES_MOUSE_VERSION */
oldch = minus;
}
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.");
}
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, "bksp -- undo move h-+-l 4-+-6\n");
(void) waddstr(helpwin, "a -- autojump /|\\ /|\\ \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. Use F/B to review the path.\n");
(void) 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 bool
chksqr(int r1, int c1)
{
if ((r1 < 0) || (r1 > BDEPTH - 1))
return (FALSE);
if ((c1 < 0) || (c1 > BWIDTH - 1))
return (FALSE);
return ((!board[r1][c1]) ? TRUE : FALSE);
}
static bool
chkmoves(int rw, int col)
/* check to see if valid moves are available */
{
unsigned n;
for (n = 0; n < SIZEOF(offsets); n++)
if (chksqr(rw + offsets[n].y, col + offsets[n].x))
return (TRUE);
return (FALSE);
}
static void
dosquares(void)
{
int i, j;
mvaddstr(0, 20, "KNIGHT'S MOVE -- a logical solitaire");
move(BOARDY, BOARDX);
waddch(boardwin, ACS_ULCORNER);
for (j = 0; j < 7; j++) {
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_TTEE);
}
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_URCORNER);
for (i = 1; i < BDEPTH; i++) {
move(BOARDY + i * 2 - 1, BOARDX);
waddch(boardwin, ACS_VLINE);
for (j = 0; j < BWIDTH; 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_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_PLUS);
}
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_RTEE);
}
move(BOARDY + i * 2 - 1, BOARDX);
waddch(boardwin, ACS_VLINE);
for (j = 0; j < BWIDTH; j++) {
waddch(boardwin, ' ');
waddch(boardwin, ' ');
waddch(boardwin, ' ');
waddch(boardwin, ACS_VLINE);
}
move(BOARDY + i * 2, BOARDX);
waddch(boardwin, ACS_LLCORNER);
for (j = 0; j < BWIDTH - 1; j++) {
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_HLINE);
waddch(boardwin, ACS_BTEE);
}
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)
{
unsigned n;
for (n = 0; n < SIZEOF(offsets); n++) {
if (chksqr(prow + offsets[n].y, pcol + offsets[n].x)) {
cellmove(prow + offsets[n].y, pcol + offsets[n].x);
waddch(boardwin, mark);
}
}
}
static void
find_next_move(int *y, int *x)
{
unsigned j, k;
int found = -1;
int first = -1;
int next = 0;
int oldy, oldx;
int newy, newx;
if (movecount > 1) {
oldy = history[movecount - 1].y;
oldx = history[movecount - 1].x;
for (j = 0; j < SIZEOF(offsets) * 2; j++) {
k = j % SIZEOF(offsets);
newy = oldy + offsets[k].y;
newx = oldx + offsets[k].x;
if (chksqr(newy, newx)) {
if (first < 0)
first = k;
if (newy == *y
&& newx == *x) {
found = k;
} else if (found >= 0) {
next = k;
break;
}
}
}
if (found < 0)
next = first;
if (next >= 0) {
*y = oldy + offsets[next].y;
*x = oldx + offsets[next].x;
}
} else {
beep();
}
}
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)
{
cellmove(row, column);
waddch(boardwin, '\b');
waddch(boardwin, tchar);
waddch(boardwin, tchar);
waddch(boardwin, tchar);
}
static void
drawmove(chtype tchar, int oldy, int oldx, int row, int column)
/* place the stars, update board & currents */
{
if (movecount <= 1) {
int i, j;
for (i = 0; i < BDEPTH; i++) {
for (j = 0; j < BWIDTH; j++) {
if (movecount == 0) {
unmarkcell(i, j);
} else {
cellmove(i, j);
if (winch(boardwin) == minus)
waddch(boardwin, movecount ? ' ' : minus);
}
}
}
} else {
markcell(tchar, oldy, oldx);
mark_possibles(oldy, oldx, ' ');
}
if (row != -1 && column != -1) {
markcell(trail, row, column);
mark_possibles(row, column, minus);
board[row][column] = TRUE;
}
wprintw(msgwin, "\nMove %d", movecount);
if (trialcount != movecount)
wprintw(msgwin, " (%d tries)", trialcount);
wclrtoeol(msgwin);
}
static int
iabs(int num)
{
if (num < 0)
return (-num);
else
return (num);
}
static bool
evalmove(int row, int column)
/* evaluate move */
{
if (movecount == 1)
return (TRUE);
else if (board[row][column] == TRUE) {
waddstr(msgwin, "\nYou've already been there.");
return (FALSE);
} else {
int rdif = iabs(row - history[movecount - 1].y);
int cdif = iabs(column - history[movecount - 1].x);
if (!((rdif == 1) && (cdif == 2)) && !((rdif == 2) && (cdif == 1))) {
waddstr(msgwin, "\nThat's not a legal knight's move.");
return (FALSE);
}
}
return (TRUE);
}
static int
completed(void)
{
int i, j, count = 0;
for (i = 0; i < BDEPTH; i++)
for (j = 0; j < BWIDTH; j++)
if (board[i][j] != 0)
count += 1;
return (count == (BWIDTH * BDEPTH) ? -1 : count);
}
static void
no_previous_move(void)
{
waddstr(msgwin, "\nNo previous move.");
beep();
}
static void
play(void)
/* play the game */
{
bool keyhelp; /* TRUE if keystroke help is up */
int i, j, count;
int lastcol = 0; /* last location visited */
int lastrow = 0;
int ny = 0, nx = 0;
int review = 0; /* review history */
int rw = 0, col = 0; /* current row and column */
do {
/* clear screen and draw board */
werase(boardwin);
werase(helpwin);
werase(msgwin);
dosquares();
help1();
wnoutrefresh(stdscr);
wnoutrefresh(helpwin);
wnoutrefresh(msgwin);
wnoutrefresh(boardwin);
doupdate();
movecount = 0;
for (i = 0; i < BDEPTH; i++) {
for (j = 0; j < BWIDTH; j++) {
board[i][j] = FALSE;
unmarkcell(i, j);
}
}
memset(history, 0, sizeof(history));
history[0].y = history[0].x = -1;
history[1].y = history[1].x = -1;
lastrow = lastcol = -2;
movecount = 1;
trialcount = 1;
keyhelp = FALSE;
show_help(&keyhelp);
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);
switch (wgetch(boardwin)) {
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;
#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 */
case KEY_B2:
case '\n':
case ' ':
review = 0;
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++;
trialcount++;
if (!chkmoves(rw, col)) {
if (completed() < 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 (movecount <= 0) {
no_previous_move();
} else if (movecount <= 1) {
ny = history[movecount].y;
nx = history[movecount].x;
if (nx < 0 || ny < 0) {
ny = lastrow;
nx = lastcol;
}
movecount = 0;
board[ny][nx] = FALSE;
oldch = minus;
drawmove(' ', ny, nx, -1, -1);
movecount = 1;
trialcount = 1;
no_previous_move();
} else {
int oldy = history[movecount - 1].y;
int oldx = history[movecount - 1].x;
if (!board[rw][col]) {
cellmove(rw, col);
waddch(boardwin, ' ');
}
board[oldy][oldx] = FALSE;
--movecount;
ny = history[movecount - 1].y;
nx = history[movecount - 1].x;
if (nx < 0 || ny < 0) {
ny = oldy;
nx = oldx;
}
drawmove(' ', 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;
find_next_move(&ny, &nx);
break;
case 'F':
if (review > 0) {
review--;
ny = history[movecount - review - 1].y;
nx = history[movecount - review - 1].x;
} else {
beep();
}
break;
case 'B':
if (review < movecount - 2) {
review++;
ny = history[movecount - review - 1].y;
nx = history[movecount - review - 1].x;
} else {
beep();
}
break;
case KEY_REDO:
case '\f':
case 'r':
clearok(curscr, TRUE);
wnoutrefresh(stdscr);
wnoutrefresh(boardwin);
wnoutrefresh(msgwin);
wnoutrefresh(helpwin);
doupdate();
break;
case 'q':
case 'x':
goto dropout;
case '?':
show_help(&keyhelp);
break;
default:
beep();
break;
}
col = nx % BWIDTH;
rw = ny % BDEPTH;
}
dropout:
if ((count = completed()) < 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');
}
int
main(int argc GCC_UNUSED, char *argv[]GCC_UNUSED)
{
init_program();
play();
endwin();
ExitProgram(EXIT_SUCCESS);
}
/* knight.c ends here */
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