Puzzle 3: Consolidate 3a/3b programs into `3` with `-p` option

Like the later puzzles

3 files changed, 80 insertions, 69 deletions

diff --git a/3b.c b/3.c
index 84455e1..6cb68db 100644
--- a/3b.c
+++ b/3.c
@@ -2,6 +2,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <unistd.h>
 
 
 int
@@ -38,7 +39,48 @@ min3(int a, int b, int c)
 
 
 int
-main()
+rucksack_common_sum()
+{
+	char buf[BUFSIZ];
+	int score = 0;
+
+	while (fgets(buf, sizeof(buf), stdin)) {
+		int len, i, j;
+
+		len = strlen(buf);
+		if (len && buf[len - 1] == '\n')
+			--len;
+		if (len % 2 == 1) {
+			fprintf(stderr, "Unexpected length: %d\n", len);
+			return -1;
+		}
+
+		qsort(buf, len / 2, 1, chrcmp);
+		qsort(buf + len / 2, len / 2, 1, chrcmp);
+
+		i = 0;
+		j = len / 2;
+		while (i < len / 2 && j < len) {
+			if (buf[i] < buf[j])
+				++i;
+			else if (buf[j] < buf[i])
+				++j;
+			else
+				break;
+		}
+		if (i >= len / 2 || j >= len) {
+			fprintf(stderr, "No match found in %s\n", buf);
+			return -1;
+		}
+		score += priority(buf[i]);
+	}
+
+	return score;
+}
+
+
+int
+group_badge_sum()
 {
 	char buf[3][BUFSIZ];
 	int score = 0;
@@ -55,8 +97,10 @@ main()
 				--len;
 				buf[n][len] = '\0';
 			}
-			if (len % 2 == 1)
+			if (len % 2 == 1) {
 				fprintf(stderr, "Unexpected length: %d\n", len);
+				return -1;
+			}
 
 			qsort(buf[n], len, 1, chrcmp);
 		}
@@ -80,7 +124,39 @@ main()
 		score += priority(buf[0][i]);
 	}
 
-	printf("Score: %d\n", score);
+	return score;
+}
+
+
+int
+main(int argc, char ** argv)
+{
+	int part = 1, i;
+
+	while ((i = getopt(argc, argv, "p:")) != -1) {
+		switch (i) {
+		case 'p':
+			part = atoi(optarg);
+			break;
+
+		default:
+			return -1;
+		}
+	}
+
+	switch (part) {
+	case 1:
+		printf("Score: %d\n", rucksack_common_sum());
+		break;
+
+	case 2:
+		printf("Score: %d\n", group_badge_sum());
+		break;
+
+	default:
+		fprintf(stderr, "Unexpected puzzle part %d\n", part);
+		return -1;
+	}
 
 	return 0;
 }
diff --git a/3a.c b/3a.c
deleted file mode 100644
index 676db86..0000000
--- a/3a.c
+++ /dev/null
@@ -1,65 +0,0 @@
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-
-int
-chrcmp(void const * a, void const * b)
-{
-	return (*(char const *) a) - *((char const *) b);
-}
-
-
-int
-priority(int c)
-{
-	if (c >= 'A' && c <= 'Z')
-		return 27 + c - 'A';
-	if (c >= 'a' && c <= 'z')
-		return 1 + c - 'a';
-	fprintf(stderr, "Unexpected priority request: %c\n", c);
-	return -1;
-}
-
-
-int
-main()
-{
-	char buf[BUFSIZ];
-	int score = 0;
-
-	while (fgets(buf, sizeof(buf), stdin)) {
-		int len, i, j;
-
-		len = strlen(buf);
-		if (len && buf[len - 1] == '\n')
-			--len;
-		if (len % 2 == 1)
-			fprintf(stderr, "Unexpected length: %d\n", len);
-
-		qsort(buf, len / 2, 1, chrcmp);
-		qsort(buf + len / 2, len / 2, 1, chrcmp);
-
-		i = 0;
-		j = len / 2;
-		while (i < len / 2 && j < len) {
-			if (buf[i] < buf[j])
-				++i;
-			else if (buf[j] < buf[i])
-				++j;
-			else
-				break;
-		}
-		if (i >= len / 2 || j >= len) {
-			fprintf(stderr, "No match found in %s\n", buf);
-			return -1;
-		}
-		score += priority(buf[i]);
-	}
-
-	printf("Score: %d\n", score);
-
-	return 0;
-}
-
diff --git a/makefile b/makefile
index 048a599..ad777c2 100644
--- a/makefile
+++ b/makefile
@@ -4,7 +4,7 @@ CFLAGS=-Wall -O2
 all: bin \
 	bin/1 \
 	bin/2 \
-	bin/3a bin/3b \
+	bin/3 \
 	bin/4a bin/4b \
 	bin/5 \
 	bin/6 \