Digital-Research-Source-Code/CPM OPERATING SYSTEMS/CPM 8000 (CPM8K)/P-CP M-Z8K SOURCES/games/tictac.c

/*
 * 3D Tic Tac Toe.
 */
#include "stdio.h"
#define	EMPTY	0
#define	PLAYER	1
#define	BEAST	5

/*
 * This is a table of all winning
 * combinations.
 * I stole it out of Kilobaud, April
 * 78.
 * You can look there to see how it
 * is ordered.
 */
char	w[] = {
	0,	1,	2,	3,
	4,	5,	6,	7,
	8,	9,	10,	11,
	12,	13,	14,	15,
	0,	4,	8,	12,
	1,	5,	9,	13,
	2,	6,	10,	14,
	3,	7,	11,	15,
	0,	5,	10,	15,
	3,	6,	9,	12,
	16,	17,	18,	19,
	20,	21,	22,	23,
	24,	25,	26,	27,
	28,	29,	30,	31,
	16,	20,	24,	28,
	17,	21,	25,	29,
	18,	22,	26,	30,
	19,	23,	27,	31,
	16,	21,	26,	31,
	19,	22,	25,	28,
	32,	33,	34,	35,
	36,	37,	38,	39,
	40,	41,	42,	43,
	44,	45,	46,	47,
	32,	36,	40,	44,
	33,	37,	41,	45,
	34,	38,	42,	46,
	35,	39,	43,	47,
	32,	37,	42,	47,
	35,	38,	41,	44,
	48,	49,	50,	51,
	52,	53,	54,	55,
	56,	57,	58,	59,
	60,	61,	62,	63,
	48,	52,	56,	60,
	49,	53,	57,	61,
	50,	54,	58,	62,
	51,	55,	59,	63,
	48,	53,	58,	63,
	51,	54,	57,	60,
	0,	16,	32,	48,
	1,	17,	33,	49,
	2,	18,	34,	50,
	3,	19,	35,	51,
	4,	20,	36,	52,
	5,	21,	37,	53,
	6,	22,	38,	54,
	7,	23,	39,	55,
	8,	24,	40,	56,
	9,	25,	41,	57,
	10,	26,	42,	58,
	11,	27,	43,	59,
	13,	29,	45,	61,
	12,	28,	44,	60,
	14,	30,	46,	62,
	15,	31,	47,	63,
	0,	21,	42,	63,
	4,	21,	38,	55,
	8,	25,	42,	59,
	12,	25,	38,	51,
	1,	21,	41,	61,
	13,	25,	37,	49,
	2,	22,	42,	62,
	14,	26,	38,	50,
	3,	22,	41,	60,
	7,	22,	37,	52,
	11,	26,	41,	56,
	15,	26,	37,	48,
	0,	20,	40,	60,
	0,	17,	34,	51,
	3,	18,	33,	48,
	3,	23,	43,	63,
	12,	24,	36,	48,
	12,	29,	46,	63,
	15,	30,	45,	60,
	15,	27,	39,	51
};

/*
 * This is the board.
 * Starts off all empty.
 */
char	b[64];

char	*sep	 = "----------- ----------- ----------- -----------";

/*
 * The mainline is just
 * a driver.
 */
main(argc, argv)
char *argv[];
{
	char buf[20];

	printf("Do you want the rules? ");
	gets(buf);
	if(buf[0]=='Y' || buf[0]=='y')
		rules();
	printf("Do you want to go first? ");
	gets(buf);
	if(buf[0]=='Y' || buf[0]=='y')
		user();
	for(;;) {
		beast();
		user();
	}
}

/*
 * Print the rules of the
 * game.
 */
rules()
{
	printf("Three dimensional tic-tac-toe is played on a 4x4x4\n");
	printf("board. To win you must get 4 in a row.  Your moves\n");
	printf("are specified as a 3 digit number; the first digit\n");
	printf("is the level, the second the row and the third the\n");
	printf("column. Levels and columns  go  from left to right\n");
	printf("from 0 to 3. Rows go from top to bottom with  0 on\n");
	printf("the top.\n");
}

/*
 * Accept a user move.
 * Exit if he wins.
 */
user()
{
	register int i, j, t;
	char buf[20];

	board();
	for(;;) {
		printf("Your move? ");
		if(gets(buf) == NULL) {
			printf("Chicken.\n");
			exit(0);
		}
		i = 16*(buf[0]-'0') + (buf[1]-'0') + 4*(buf[2]-'0');
		if(i>=0 && i<=63 && b[i]==EMPTY)
			break;
		printf("Eh?\n");
	}
	b[i] = PLAYER;
	for(i=0; i<4*76; i+=4) {
		t = 0;
		for(j=0; j<4; ++j)
			t += b[w[i+j]];
		if(t == 4*PLAYER) {
			printf("You win.\n");
			exit(0);
		}
	}
}

/*
 * Display the board.
 * Not as easy as it sounds.
 */
board()
{
	register int i, j;

	for(i=0; i<4; ++i) {
		if(i != 0)
			puts(sep);
		for(j=0; j<64; j+=4) {
			psq(i+j);
			if(j==12 || j==28 || j==44)
				putchar(' ');
			else if(j >= 60)
				putchar('\n');
			else
				putchar('!');
		}
	}
}

/*
 * Format and put out square
 * `s' of the board.
 */
psq(s)
{
	register int v;

	v = b[s];
	if(v == PLAYER)
		printf("UU");
	else if(v == BEAST)
		printf("CC");
	else
		printf("  ");
}

/*
 * Move for the machine.
 * Just exit on machine wins
 * and draws.
 */
beast()
{
	register int i, j, t;
	int s, bs, bt, v[76];

	for(i=0; i<4*76; i+=4) {
		t = 0;
		for(j=0; j<4; ++j)
			t += b[w[i+j]];
		v[i>>2] = t;
		if(t == 3*BEAST)
			break;
	}
	if(i < 4*76) {
		for(j=0; j<4; ++j)
			if(b[w[i+j]] == EMPTY) {
				b[w[i+j]] = BEAST;
				break;
			}
		board();
		printf("I win.\n");
		exit(0);
	}
	bt = 0;
	for(s=0; s<64; ++s) {
		if(b[s] != EMPTY)
			continue;
		t = 0;
		for(i=0; i<4*76; i+=4) {
			for(j=0; j<4; ++j)
				if(w[i+j] == s)
					break;
			if(j != 4) {
				if(v[i>>2] == 3*PLAYER) {
					b[s] = BEAST;
					return;
				}
				t += weight(v[i>>2]);
			}
		}
		if(t > bt) {
			bt = t;
			bs = s;
		}
	}
	if(bt != 0)
		b[bs] = BEAST;
	else {
		for(s=0; s<64; ++s)
			if(b[s] == EMPTY)
				break;
		if(s == 64) {
			printf("Draw.\n");
			exit(0);
		}
		b[s] = BEAST;
	}
}

/*
 * Given a total along a winning
 * combination, return the weight
 * value.
 */
weight(at)
{
	register int t;

	t = at;
	if(t == PLAYER)
		return(1);
	if(t == 2*PLAYER)
		return(4);
	if(t == BEAST)
		return(1);
	if(t == 2*BEAST)
		return(2);
	return(0);
}