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/*
 *	Name: Towers of Hanoi.
 *
 *	Desc:
 *		This is a playable copy of towers of hanoi.
 *		Its sole purpose is to demonstrate my Amiga Curses package.
 *		This program should compile on any system that has Curses.
 *		'hanoi'		will give a manual game with 7 playing pieces.
 *		'hanoi n'	will give a manual game with n playing pieces.
 *		'hanoi n a' will give an auto solved game with n playing pieces.
 *
 *	Author: Simon J Raybould	(sie@fulcrum.bt.co.uk).
 * 	(This version has been slightly modified by the ncurses maintainers.)
 *
 *	Date: 05.Nov.90
 *
 * $Id: hanoi.c,v 1.34 2012/12/08 16:41:56 tom Exp $
 */

#include <test.priv.h>
#include <math.h>

#define NPEGS			3	/* This is not configurable !! */
#define MINTILES		3
#define MAXTILES		9
#define DEFAULTTILES		7
#define TOPLINE			6
#define BASELINE		16
#define STATUSLINE		(LINES-3)
#define LEFTPEG			19
#define MIDPEG			39
#define RIGHTPEG		59

#define LENTOIND(x)		(((int)(x)-1)/2)
#define OTHER(a,b)		(3-((a)+(b)))

struct Peg {
    size_t Length[MAXTILES];
    int Count;
};

static struct Peg Pegs[NPEGS];
static int PegPos[] =
{
    LEFTPEG,
    MIDPEG,
    RIGHTPEG
};
static short TileColour[] =
{
    COLOR_GREEN,		/* Length 3 */
    COLOR_MAGENTA,		/* Length 5 */
    COLOR_RED,			/* Length 7 */
    COLOR_BLUE,			/* Length 9 */
    COLOR_CYAN,			/* Length 11 */
    COLOR_YELLOW,		/* Length 13 */
    COLOR_GREEN,		/* Length 15 */
    COLOR_MAGENTA,		/* Length 17 */
    COLOR_RED,			/* Length 19 */
};
static int NTiles = 0;
static int NMoves = 0;
static bool AutoFlag = FALSE;

static void InitTiles(void);
static void DisplayTiles(void);
static void MakeMove(int From, int To);
static void AutoMove(int From, int To, int Num);
static void Usage(void);
static int Solved(int NumTiles);
static int GetMove(int *From, int *To);
static int InvalidMove(int From, int To);

int
main(int argc, char **argv)
{
    int FromCol, ToCol;

    setlocale(LC_ALL, "");

    switch (argc) {
    case 1:
	NTiles = DEFAULTTILES;
	break;
    case 2:
	NTiles = atoi(argv[1]);
	if (NTiles > MAXTILES || NTiles < MINTILES) {
	    fprintf(stderr, "Range %d to %d\n", MINTILES, MAXTILES);
	    ExitProgram(EXIT_FAILURE);
	}
	break;
    case 3:
	if (strcmp(argv[2], "a")) {
	    Usage();
	    ExitProgram(EXIT_FAILURE);
	}
	NTiles = atoi(argv[1]);
	if (NTiles > MAXTILES || NTiles < MINTILES) {
	    fprintf(stderr, "Range %d to %d\n", MINTILES, MAXTILES);
	    ExitProgram(EXIT_FAILURE);
	}
	AutoFlag = TRUE;
	break;
    default:
	Usage();
	ExitProgram(EXIT_FAILURE);
    }
    initscr();
    if (has_colors()) {
	int i;
	short bg = COLOR_BLACK;
	start_color();
#if HAVE_USE_DEFAULT_COLORS
	if (use_default_colors() == OK)
	    bg = -1;
#endif
	for (i = 0; i < 9; i++)
	    init_pair((short) (i + 1), bg, TileColour[i]);
    }
    cbreak();
    if (LINES < 24) {
	endwin();
	fprintf(stderr, "Min screen length 24 lines\n");
	ExitProgram(EXIT_FAILURE);
    }
    if (AutoFlag) {
	curs_set(0);
	leaveok(stdscr, TRUE);	/* Attempt to remove cursor */
    }
    InitTiles();
    DisplayTiles();
    if (AutoFlag) {
	do {
	    noecho();
	    AutoMove(0, 2, NTiles);
	} while (!Solved(NTiles));
	sleep(2);
    } else {
	echo();
	for (;;) {
	    if (GetMove(&FromCol, &ToCol))
		break;
	    if (InvalidMove(FromCol, ToCol)) {
		MvAddStr(STATUSLINE, 0, "Invalid Move !!");
		refresh();
		beep();
		continue;
	    }
	    MakeMove(FromCol, ToCol);
	    if (Solved(NTiles)) {
		MvPrintw(STATUSLINE, 0,
			 "Well Done !! You did it in %d moves", NMoves);
		refresh();
		sleep(5);
		break;
	    }
	}
    }
    endwin();
    ExitProgram(EXIT_SUCCESS);
}

static int
InvalidMove(int From, int To)
{
    if (From >= NPEGS)
	return TRUE;
    if (From < 0)
	return TRUE;
    if (To >= NPEGS)
	return TRUE;
    if (To < 0)
	return TRUE;
    if (From == To)
	return TRUE;
    if (!Pegs[From].Count)
	return TRUE;
    if (Pegs[To].Count &&
	Pegs[From].Length[Pegs[From].Count - 1] >
	Pegs[To].Length[Pegs[To].Count - 1])
	return TRUE;
    return FALSE;
}

static void
InitTiles(void)
{
    int Size, SlotNo;

    for (Size = NTiles * 2 + 1, SlotNo = 0; Size >= 3; Size -= 2)
	Pegs[0].Length[SlotNo++] = (size_t) Size;

    Pegs[0].Count = NTiles;
    Pegs[1].Count = 0;
    Pegs[2].Count = 0;
}

static void
DisplayTiles(void)
{
    int Line, peg, SlotNo;
    char TileBuf[BUFSIZ];

    erase();
    MvAddStr(1, 24, "T O W E R S   O F   H A N O I");
    MvAddStr(3, 34, "SJR 1990");
    MvPrintw(19, 5, "Moves : %d of %.0f", NMoves, pow(2.0, NTiles) - 1);
    (void) attrset(A_REVERSE);
    MvAddStr(BASELINE, 8,
	     "                                                               ");

    for (Line = TOPLINE; Line < BASELINE; Line++) {
	MvAddCh(Line, LEFTPEG, ' ');
	MvAddCh(Line, MIDPEG, ' ');
	MvAddCh(Line, RIGHTPEG, ' ');
    }
    MvAddCh(BASELINE, LEFTPEG, '1');
    MvAddCh(BASELINE, MIDPEG, '2');
    MvAddCh(BASELINE, RIGHTPEG, '3');
    (void) attrset(A_NORMAL);

    /* Draw tiles */
    for (peg = 0; peg < NPEGS; peg++) {
	for (SlotNo = 0; SlotNo < Pegs[peg].Count; SlotNo++) {
	    size_t len = Pegs[peg].Length[SlotNo];
	    if (len < sizeof(TileBuf) - 1 && len < (size_t) PegPos[peg]) {
		memset(TileBuf, ' ', len);
		TileBuf[len] = '\0';
		if (has_colors())
		    (void) attrset((attr_t) COLOR_PAIR(LENTOIND(len)));
		else
		    (void) attrset(A_REVERSE);
		MvAddStr(BASELINE - (SlotNo + 1),
			 (PegPos[peg] - (int) len / 2),
			 TileBuf);
	    }
	}
    }
    (void) attrset(A_NORMAL);
    refresh();
}

static int
GetMove(int *From, int *To)
{
    MvAddStr(STATUSLINE, 0, "Next move ('q' to quit) from ");
    clrtoeol();
    refresh();
    if ((*From = getch()) == 'q')
	return TRUE;
    *From -= ('0' + 1);
    addstr(" to ");
    clrtoeol();
    refresh();

    if ((*To = getch()) == 'q')
	return TRUE;
    *To -= ('0' + 1);
    refresh();
    if (!AutoFlag)
	napms(500);

    move(STATUSLINE, 0);
    clrtoeol();
    refresh();
    return FALSE;
}

static void
MakeMove(int From, int To)
{
    Pegs[From].Count--;
    Pegs[To].Length[Pegs[To].Count] = Pegs[From].Length[Pegs[From].Count];
    Pegs[To].Count++;
    NMoves++;
    DisplayTiles();
}

static void
AutoMove(int From, int To, int Num)
{
    if (Num == 1) {
	MakeMove(From, To);
	napms(500);
    } else {
	AutoMove(From, OTHER(From, To), Num - 1);
	MakeMove(From, To);
	napms(500);
	AutoMove(OTHER(From, To), To, Num - 1);
    }
}

static int
Solved(int NumTiles)
{
    int i;

    for (i = 1; i < NPEGS; i++)
	if (Pegs[i].Count == NumTiles)
	    return TRUE;
    return FALSE;
}

static void
Usage(void)
{
    fprintf(stderr, "Usage: hanoi [<No Of Tiles>] [a]\n");
    fprintf(stderr,
	    "The 'a' option causes the tower to be solved automatically\n");
}