From: Mart Lubbers <mart@martlubbers.net>
Date: Mon, 6 Dec 2021 08:34:56 +0000 (+0100)
Subject: speed up
X-Git-Url: https://git.martlubbers.net/?a=commitdiff_plain;h=2d015db00d7612786a98db0cdfda291b6dc08389;p=advent21.git

speed up
---

diff --git a/06a.c b/06a.c
index 92a1b8a..c9152c6 100644
--- a/06a.c
+++ b/06a.c
@@ -7,28 +7,17 @@ int main()
 	char buf[1000];
 	if (fgets(buf, 1000, stdin) == NULL)
 		return 1;
-	long fish0[9] = {0};
-	long fish1[9] = {0};
-	long *this = &fish0[0];
-	long *that = &fish1[0];
-
+	long fish[9] = {0};
 	char *p = strtok(buf, ",");
-	this[atoi(p)]++;
+	fish[atoi(p)]++;
 	while ((p = strtok(NULL, ",")) != NULL)
-		this[atoi(p)]++;
+		fish[atoi(p)]++;
 
-	for (long day = 0; day<80; day++) {
-		that[8] = this[0];
-		for (long i = 0; i<8; i++)
-			that[i] = this[i+1];
-		that[6] += this[0];
-		long *tmp = this;
-		this = that;
-		that = tmp;
-	}
+	for (long day = 0; day<80; day++)
+		fish[(day+7) % 9] += fish[day%9];
 
 	long sum = 0;
 	for (long i = 0; i<=8; i++)
-		sum += this[i];
+		sum += fish[i];
 	printf("%lu\n", sum);
 }
diff --git a/06b.c b/06b.c
index abc9892..0b2f076 100644
--- a/06b.c
+++ b/06b.c
@@ -7,28 +7,17 @@ int main()
 	char buf[1000];
 	if (fgets(buf, 1000, stdin) == NULL)
 		return 1;
-	long fish0[9] = {0};
-	long fish1[9] = {0};
-	long *this = &fish0[0];
-	long *that = &fish1[0];
-
+	long fish[9] = {0};
 	char *p = strtok(buf, ",");
-	this[atoi(p)]++;
+	fish[atoi(p)]++;
 	while ((p = strtok(NULL, ",")) != NULL)
-		this[atoi(p)]++;
+		fish[atoi(p)]++;
 
-	for (long day = 0; day<256; day++) {
-		that[8] = this[0];
-		for (long i = 0; i<8; i++)
-			that[i] = this[i+1];
-		that[6] += this[0];
-		long *tmp = this;
-		this = that;
-		that = tmp;
-	}
+	for (long day = 0; day<256; day++)
+		fish[(day+7) % 9] += fish[day%9];
 
 	long sum = 0;
 	for (long i = 0; i<=8; i++)
-		sum += this[i];
+		sum += fish[i];
 	printf("%lu\n", sum);
 }