1 files changed, 78 insertions, 0 deletions
diff --git a/2020/12/part1.c b/2020/12/part1.c
new file mode 100644
index 0000000..7ee0f4a
--- /dev/null
+++ b/2020/12/part1.c
@@ -0,0 +1,78 @@
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <malloc.h>
+#include <string.h>
+
+#define MAX_INPUT_WIDTH 128
+#define MAX_INPUT_HEIGTH 128
+#define MAX_INPUT MAX_INPUT_WIDTH * MAX_INPUT_HEIGTH
+
+enum direction {
+    North,
+    East,
+    South,
+    West
+};
+
+int solve(const char *filename)
+{
+    FILE *file = fopen(filename, "r");
+
+    // Include space for newline and string terminator
+    char buffer[8] = { 0 };
+
+    enum direction dir = East;
+    int hor = 0;
+    int ver = 0;
+    while (fgets(buffer, 8, file)) {
+        int n = atoi(buffer + 1);
+        switch (buffer[0]) {
+            case 'N':
+                ver += n;
+                break;
+            case 'E':
+                hor += n;
+                break;
+            case 'S':
+                ver -= n;
+                break;
+            case 'W':
+                hor -= n;
+                break;
+            case 'F':
+                switch (dir) {
+                    case North:
+                        ver += n;
+                        break;
+                    case East:
+                        hor += n;
+                        break;
+                    case South:
+                        ver -= n;
+                        break;
+                    case West:
+                        hor -= n;
+                        break;
+                }
+                break;
+            case 'R':
+                dir = (enum direction)(((int)dir + (n / 90)) % 4);
+                break;
+            case 'L':
+                dir = (enum direction)((abs(4 + ((int)dir - (n / 90))) % 4));
+                break;
+            default:
+                break;
+        }
+    }
+
+    fclose(file);
+
+    return abs(ver) + abs(hor);
+}
+
+int main(int argc, char *argv[])
+{
+    printf("%i\n", solve(argv[argc - 1]));
+}