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hotpotato_checked.cfa @ e78966e

Last change on this file since e78966e was f0c9c9b, checked in by Peter A. Buhr <pabuhr@…>, 10 months ago
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Property mode set to `100644`
File size: 7.0 KB

Rev	Line
[fd775ae]	1	#include <fstream.hfa> // sin/sout
	2	#include <stdlib.hfa> // convert
	3	#include <string.h>
	4	#include <coroutine.hfa>
	5
	6	struct Potato {
[f0c9c9b]	7	PRNG & prng;
	8	unsigned int deadline; // when timer goes off
	9	unsigned int timer; // up counter to deadline
[fd775ae]	10	}; // Potato
	11
	12	void reset( Potato & potato, unsigned int maxTicks = 10 );
	13	void ?{}( Potato & potato, PRNG & prng, unsigned int maxTicks = 10 );
	14
	15	void ?{}( Potato & potato, PRNG & prng, unsigned int maxTicks ) with(potato) {
	16	&potato.prng = &prng;
	17	reset( potato, maxTicks );
[f0c9c9b]	18	} // Potato
[fd775ae]	19
	20	coroutine Player {
[f0c9c9b]	21	PRNG & prng;
	22	int id; // player identity
	23	Potato & potato; // potato being tossed
	24	Player * partner[2]; // left and right player
[fd775ae]	25	}; // Player
	26
	27	void ?{}( Player & player, PRNG & prng, unsigned int id, Potato & potato ) {
	28	&player.prng = &prng;
	29	player.id = id;
	30	&player.potato = &potato;
[f0c9c9b]	31	} // Player
[fd775ae]	32
	33	Player & umpire;
	34
	35	ExceptionDecl( Explode );
	36	ExceptionDecl( Terminate, Player * victim; );
[26be854]	37	ExceptionDecl( Election );
[fd775ae]	38	ExceptionDecl( cmd_error ); // convert(...) throws out_of_range or invalid_argument
	39
	40	void reset( Potato & potato, unsigned int maxTicks ) with(potato) {
[f0c9c9b]	41	if ( maxTicks < 2 ) abort( "Hot Potato initialized with less than 2 ticks" ); // optional
[fd775ae]	42	deadline = prng( prng, 1, maxTicks );
	43	timer = 0;
	44	sout \| " POTATO goes off after " \| deadline \| " tick" \| nosep \| (deadline > 1 ? "s" : "");
	45	} // reset
	46
	47	void countdown( Potato & potato ) with(potato) {
	48	timer += 1;
[26be854]	49	if ( timer == deadline ) throwResume ExceptionInst( Explode );
[fd775ae]	50	} // countdown
	51
	52	static unsigned int rightOf( unsigned int me, unsigned int total ) {
	53	return ( me + 1 ) % total;
	54	} // rightOf
	55
	56	static unsigned int leftOf( unsigned int me, unsigned int total ) {
	57	return ( me + total - 1) % total;
	58	} // leftOf
	59
	60	enum { LEFT = 0, RIGHT = 1 };
	61
	62	static void vote( Player & player ) { // cause partner to vote
	63	resume( player ); checked_poll();
	64	} // vote
	65
	66	static void terminate( Player & player ) { // resume umpire
	67	resume( player );
[f0c9c9b]	68	checked_poll();
	69	sout \| "THIS SHOULD NOT BE REACHED";
[fd775ae]	70	} // terminate
	71
	72	void init( Player & player, Player & lp, Player & rp ) with(player) { // supply partners
	73	partner[LEFT] = &lp;
	74	partner[RIGHT] = &rp;
	75	resume( player ); // establish main as starter for termination
[f0c9c9b]	76	checked_poll();
[fd775ae]	77	} // init
	78
	79	int getId( Player & player ) { // player id
	80	return player.id;
	81	} // getId
	82
	83	void toss( Player & player ) { // tossed the potato
[f0c9c9b]	84	resume( player );
[fd775ae]	85	checked_poll();
	86	} // toss
	87
	88	void main( Player & player ) with(player) {
	89	try {
[f0c9c9b]	90	enable_ehm(); // allow delivery of nonlocal exceptions
	91	suspend; // return immediately after establishing starter
	92	checked_poll();
	93
	94	for ( ;; ) {
	95	checked_poll();
	96	if ( partner[LEFT] == &player ) { // stop when only one player
	97	sout \| id \| " wins the Match!";
	98	return;
	99	} // exit
	100
	101	countdown( potato ); // player is eliminated if countdown() returned true
	102
	103	size_t side = prng( prng, 2 );
	104	sout \| id \| " -> " \| nonl;
	105	toss( *partner[ side ] ); // random toss left/right
	106	} // for
	107	disable_ehm();
[fd775ae]	108	} catchResume( Terminate * v ) {
	109	v->victim->partner[LEFT]->partner[RIGHT] = v->victim->partner[RIGHT]; // unlink node
	110	v->victim->partner[RIGHT]->partner[LEFT] = v->victim->partner[LEFT];
[f0c9c9b]	111	delete( v->victim );
[fd775ae]	112	reset( potato );
	113	sout \| "U " \| nonl; // start new game
	114	flush( sout );
	115	} catchResume( Election * election ) {
	116	sout \| "election";
	117	sout \| " -> " \| id \| nonl;
[f0c9c9b]	118	if ( id > getId( umpire ) ) &umpire = &player; // set umpire to highest id so far
	119	resumeAt( partner[RIGHT], election );
	120	disable_ehm(); // disable ehm since we can't handle execption thrown in vote here and want to poll later
[fd775ae]	121	vote( *partner[RIGHT] );
[f0c9c9b]	122	enable_ehm(); // enable after vote
[26be854]	123	} catchResume( Explode * ) {
[f0c9c9b]	124	sout \| id \| " is eliminated";
	125	if ( &player == &umpire ) {
	126	try {
	127	id = -1; // remove from election
	128	resumeAt( *partner[RIGHT], ExceptionInst( Election ) );
	129	vote( *partner[RIGHT] ); // start election
	130	checked_poll();
	131	} catchResume( Election * election ) {
	132	sout \| " : umpire " \| getId( umpire );
	133	} // try
	134	} // if
	135	resumeAt( umpire, ExceptionInst( Terminate, &player ) );
	136	terminate( umpire );
	137	assert( false ); // no return
	138	} // try
[fd775ae]	139	} // main
	140
	141
	142	int main( int argc, char * argv[] ) {
	143	enum {
	144	MinNoPlayers = 2, // minimum players in the game
	145	MaxNoPlayers = 10, // maximum players in the game
	146	DefaultGames = 5, // default games to play
	147	};
	148	intmax_t numGames = DefaultGames; // games to play
	149	intmax_t numPlayers = 0; // players for a particular game
	150	intmax_t seed = 42; // random-number seed
	151	bool playersSet = false;
	152	char * nosummary = getenv( "NOSUMMARY" ); // print extra output
	153
	154	try {
	155	choose ( argc ) {
	156	case 4:
	157	if ( strcmp( argv[3], "d" ) != 0 ) { // default ?
	158	seed = convert( argv[3] ); if ( seed < 1 ) throw ExceptionInst( cmd_error ); // invalid ?
	159	} // if
	160	fallthrough;
	161	case 3:
	162	if ( strcmp( argv[2], "d" ) != 0 ) { // default ?
	163	numPlayers = convert( argv[2] ); if ( numPlayers < 2 ) throw ExceptionInst( cmd_error ); // invalid ?
	164	playersSet = true;
	165	} // if
	166	fallthrough;
	167	case 2:
	168	if ( strcmp( argv[1], "d" ) != 0 ) { // default ?
	169	numGames = convert( argv[1] ); if ( numGames < 0 ) throw ExceptionInst( cmd_error ); // invalid ?
	170	} // if
	171	fallthrough;
	172	case 1: ; // defaults
	173	default: // too many arguments
[f0c9c9b]	174	throw ExceptionInst( cmd_error );
[fd775ae]	175	} // choose
	176	} catch( exception_t * ) { // catch any
	177	exit \| "Usage: " \| argv[0]
[f0c9c9b]	178	\| " [ games (>=0) \| 'd' (default " \| DefaultGames
	179	\| ") [ players (>=2) \| 'd' (random " \| MinNoPlayers \| "-" \| MaxNoPlayers
	180	\| ") [ seed (>0) \| 'd' (random) ] ] ]";
[fd775ae]	181	} // try
	182	sout \| numGames \| numPlayers \| seed;
	183
	184	PRNG mprng, hprng, pprng;
	185	if ( seed != 0 ) { // specified on command line ?
	186	set_seed( mprng, seed ); set_seed( hprng, seed ); set_seed( pprng, seed );
	187	} // if
	188
	189	for ( game; 1 ~= numGames ) {
	190	if ( ! playersSet ) numPlayers = prng( mprng, MinNoPlayers, MaxNoPlayers );
	191	sout \| numPlayers \| " players in the game";
	192	{
	193	Potato potato{ hprng }; // hot potato to be tossed
	194	Player * players[numPlayers];
	195
	196	for ( unsigned int i = 0; i < (unsigned int)numPlayers; i += 1 ) { // start the players
	197	players[i] = malloc();
	198	?{}( *players[i], pprng, i, potato );
	199	} // for
	200
	201	// Do not swap player[0] with itself.
	202	unsigned int rposn = prng( mprng, 1, numPlayers - 1 ); // swap random position with 0
	203	swap( players[0], players[rposn] );
	204
	205	// Tell each player its partner.
	206	for ( unsigned int i = 0; i < (unsigned int)numPlayers; i += 1 ) {
	207	init( players[i], players[leftOf(i, numPlayers)], *players[rightOf(i, numPlayers)] );
	208	} // for
	209
	210	&umpire = players[rposn]; // designate umpire and start game
	211	sout \| "U " \| nonl;
	212	toss( *players[rposn] );
	213	delete( &umpire );
	214	}
	215	if ( game < (unsigned int)numGames ) sout \| nl \| nl; // whitespace between games
	216	} // for
	217	} // main
	218
	219	// Local Variables: //
	220	// compile-command: "make hotpotato" //
	221	// End: //

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