feat: 1: safe rotating lock

.gitignore

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+**/*.input

day1.c

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+#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;
+}