1 files changed, 66 insertions, 0 deletions
diff --git a/2020/12/part2.c b/2020/12/part2.c
new file mode 100644
index 0000000..745b56c
--- /dev/null
+++ b/2020/12/part2.c
@@ -0,0 +1,66 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <malloc.h>
+#include <string.h>
+
+#include "../utils.h"
+
+int solve(const char *filename)
+{
+    FILE *file = fopen(filename, "r");
+
+    // Include space for newline and string terminator
+    char buffer[8] = { 0 };
+
+    int w_x = 10;
+    int w_y = 1;
+    int y = 0;
+    int x = 0;
+    while (fgets(buffer, 8, file)) {
+        int n = atoi(buffer + 1);
+        switch (buffer[0]) {
+            case 'N':
+                w_y += n;
+                break;
+            case 'E':
+                w_x += n;
+                break;
+            case 'S':
+                w_y -= n;
+                break;
+            case 'W':
+                w_x -= n;
+                break;
+            case 'F':
+                for (int i = 0; i < n; i++) {
+                    x += w_y;
+                    y += w_x;
+                }
+                break;
+            case 'R':
+                for (int i = 0; i < n / 90; i++) {
+                    SWAP(w_y, w_x);
+                    w_y = -w_y;
+                }
+                break;
+            case 'L':
+                for (int i = 0; i < n / 90; i++) {
+                    SWAP(w_y, w_x);
+                    w_x = -w_x;
+                }
+                break;
+            default:
+                break;
+        }
+    }
+
+    fclose(file);
+
+    return abs(x) + abs(y);
+}
+
+int main(int argc, char *argv[])
+{
+    printf("%i\n", solve(argv[argc - 1]));
+}