xref: /openbsd/games/cribbage/cards.c (revision f741f25e)
1 /*	$OpenBSD: cards.c,v 1.7 2015/12/31 18:10:19 mestre Exp $	*/
2 /*	$NetBSD: cards.c,v 1.3 1995/03/21 15:08:41 cgd Exp $	*/
3 
4 /*-
5  * Copyright (c) 1980, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <stdlib.h>
34 
35 #include "cribbage.h"
36 
37 /*
38  * Initialize a deck of cards to contain one of each type.
39  */
40 void
makedeck(CARD d[])41 makedeck(CARD d[])
42 {
43 	int i, j, k;
44 
45 	k = 0;
46 	for (i = 0; i < RANKS; i++)
47 		for (j = 0; j < SUITS; j++) {
48 			d[k].suit = j;
49 			d[k++].rank = i;
50 		}
51 }
52 
53 /*
54  * Given a deck of cards, shuffle it -- i.e. randomize it
55  * see Knuth, vol. 2, page 125.
56  */
57 void
shuffle(CARD d[])58 shuffle(CARD d[])
59 {
60 	int j, k;
61 	CARD c;
62 
63 	for (j = CARDS; j > 0; --j) {
64 		k = arc4random_uniform(j);	/* random 0 <= k < j */
65 		c = d[j - 1];			/* exchange (j - 1) and k */
66 		d[j - 1] = d[k];
67 		d[k] = c;
68 	}
69 }
70 
71 /*
72  * return true if the two cards are equal...
73  */
74 int
eq(CARD a,CARD b)75 eq(CARD a, CARD b)
76 {
77 	return ((a.rank == b.rank) && (a.suit == b.suit));
78 }
79 
80 /*
81  * isone returns TRUE if a is in the set of cards b
82  */
83 int
isone(CARD a,CARD b[],int n)84 isone(CARD a, CARD b[], int n)
85 {
86 	int i;
87 
88 	for (i = 0; i < n; i++)
89 		if (eq(a, b[i]))
90 			return (TRUE);
91 	return (FALSE);
92 }
93 
94 /*
95  * remove the card a from the deck d of n cards
96  */
97 void
cremove(CARD a,CARD d[],int n)98 cremove(CARD a, CARD d[], int n)
99 {
100 	int i, j;
101 
102 	for (i = j = 0; i < n; i++)
103 		if (!eq(a, d[i]))
104 			d[j++] = d[i];
105 	if (j < n)
106 		d[j].suit = d[j].rank = EMPTY;
107 }
108 
109 /*
110  * sorthand:
111  *	Sort a hand of n cards
112  */
113 void
sorthand(CARD h[],int n)114 sorthand(CARD h[], int n)
115 {
116 	CARD *cp, *endp;
117 	CARD c;
118 
119 	for (endp = &h[n]; h < endp - 1; h++)
120 		for (cp = h + 1; cp < endp; cp++)
121 			if ((cp->rank < h->rank) ||
122 			    (cp->rank == h->rank && cp->suit < h->suit)) {
123 				c = *h;
124 				*h = *cp;
125 				*cp = c;
126 			}
127 }
128