1 files changed, 35 insertions, 0 deletions

diff --git a/2023/08/8a.c b/2023/08/8a.c
new file mode 100644
index 0000000..62f6fcd
--- /dev/null
+++ b/2023/08/8a.c
@@ -0,0 +1,35 @@
+#include <inttypes.h>
+#include <math.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define N 30000
+
+bool isnum(char c) { return c >= '0' && c <= '9'; }
+int index(char *c) { return c[0]-'A' + (c[1]-'A' + (c[2]-'A')*26)*26; }
+
+int map[N][2];
+
+int main() {
+        char *buf, dir[N], line[N];
+        int n, i, s;
+
+        n = strlen(fgets(dir, N, stdin)) - 1;
+
+        fgets(line, N, stdin);
+        while ((buf = fgets(line, N, stdin)) != NULL) {
+                i = index(buf);
+                while (*buf != '(') buf++;
+                map[i][0] = index(buf+1);
+                while (*buf != ' ') buf++;
+                map[i][1] = index(buf+1);
+        }
+
+        for (i = index("AAA"), s = 0; i != index("ZZZ"); s++)
+                i = map[i][dir[s % n] == 'R'];
+
+        printf("%d\n", s);
+        return 0;
+}