+ (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 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 = (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;
+ }
+ } 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 >= 0 && column >= 0) {
+ 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);
+}