commit f8c9aba703d0afde7331fb3a7fa15321957157a4
Author: Zhongheng Liu <zhongheng@stvnliu.me>
Date:   Sun Dec 14 14:25:12 2025 +0100

    feat: 1: safe rotating lock

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..162238c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+**/*.input
diff --git a/day1.c b/day1.c
new file mode 100644
index 0000000..cd094fa
--- /dev/null
+++ b/day1.c
@@ -0,0 +1,46 @@
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+int dial_translate(int pos, int offset) {
+	int final = pos + offset;
+	int fpos = final;
+	if (final < 0) {fpos = 100 + final;}
+	if (final >= 100) {fpos = final - 100;}
+	return fpos % 100;
+}
+
+int main() {
+	int pos = 50;
+	int count = 0;
+	int fd = open("./day1.input", O_RDONLY);
+	struct stat stat;
+	fstat(fd, &stat);
+	char charbuf[stat.st_size];
+	read(fd, charbuf, stat.st_size);
+	printf("Size: %d\n", stat.st_size);
+	int p;
+	for (p = 0; p < (sizeof(charbuf) - sizeof(char)); p++) {
+		char cur = charbuf[p];
+		int direction;
+		if (cur == 'L') {direction = -1;}
+		else if (cur == 'R') {direction = 1;}
+		p++;
+		int i = 0;
+		char numline[100] = {0};
+		while (charbuf[p] != '\n') {
+			numline[i] = charbuf[p];
+			i++;
+			p++;
+		}
+		int offset = atoi(numline) * direction;
+		printf("Offset: %d\n", offset);
+		pos = dial_translate(pos, offset);
+		if (pos == 0) { count++; }
+		printf("Dial at: %d\n", pos);
+	}
+	printf("Password: %d\n", count);
+	return 0;
+}