display 2-dart checkout if different than 3-dart checkout

1 files changed, 29 insertions, 9 deletions

diff --git a/checkouts.c b/checkouts.c
index a0bfaf2..0099aa5 100644
--- a/checkouts.c
+++ b/checkouts.c
@@ -4,25 +4,45 @@
 #include <stdlib.h>
 #include <string.h>
 
-char *checkouts_suggested(int rem)
+int checkouts_suggested(char *buf, int rem, int darts_in_hand)
 {
+	buf[0] = 0;
 	if (rem < 2 || rem > 170)
-		return NULL;
+		return 0;
 
-	char *str = NULL, *p = NULL;
+	char *p = buf;
 	char *target;
-	int i = 3, trem = rem;
+	int i = darts_in_hand, trem = rem;
 	while (i && trem && (target = CHECKOUTS[--i][trem - 1])) {
-		if (i == 2)
-			p = str = malloc(3 * SEGMENT_MAX_LEN);
-		else
+		if (i < darts_in_hand - 1)
 			*p++ = '-';
 		p = stpcpy(p, target);
-
 		trem -= segment_points(segment_from_name(target));
 	}
 
-	return str;
+	return p - buf;
+}
+
+#define CHECKOUT_2_PRE " ("
+#define CHECKOUT_2_POST ")"
+// buf must be at least 32 bytes
+int checkouts_suggested_3_2(char *buf, int rem)
+{
+	int len = checkouts_suggested(buf, rem, 3);
+	if (!len)
+		return 0;
+
+	char *buf2 = buf + len + sizeof(CHECKOUT_2_PRE) - 1;
+	int len2 = checkouts_suggested(buf2, rem, 2);
+	if (!len2 ||
+		(len == len2 && !strncmp(buf, buf2, len > len2 ? len : len2)))
+		return len;
+
+	memcpy(buf + len, CHECKOUT_2_PRE, sizeof(CHECKOUT_2_PRE) - 1);
+	memcpy(buf2 + len2, CHECKOUT_2_POST, sizeof(CHECKOUT_2_POST));
+	len += sizeof(CHECKOUT_2_PRE) + len2 + sizeof(CHECKOUT_2_POST) - 2;
+
+	return len;
 }
 
 char *CHECKOUTS[][170] = {