Day10

day10/proci.c

@@ -0,0 +1,62 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define BUFFER_SIZE 64
+#define INTERESTING_CYCLES 20, 60, 100, 140, 180, 220
+#define CRT_WIDTH 40
+#define CRT_HEIGHT 6
+
+int main() {
+    char buf[BUFFER_SIZE], *p, c;
+    memset(buf, 0, BUFFER_SIZE);
+    p = buf;
+
+    int X = 1, cycle = 0, sum = 0, add, delay = 0;
+    int interesting_cycles[] = {INTERESTING_CYCLES};
+    int row =0, col = 0;
+
+    while ((c = getchar()) != EOF) {
+        *p++ = c;
+        if (c == '\n') {
+
+
+            if (sscanf(buf, "addx %i", &add)) {
+                delay = 2;
+            } else {
+                add = 0;
+                delay = 1;
+            }
+
+            while (delay > 0) {
+                cycle++;
+                if (col == CRT_WIDTH) {
+                    printf("\n");
+                    col = 0;
+                    row++;
+                }
+                if (X - 1 == col || X == col || X + 1 == col) {
+                    printf("#");
+                } else {
+                    printf(".");
+                }
+                // Update sum if we are in the right cycle
+                for (int i = 0; i < sizeof(interesting_cycles)/sizeof(int); i++) {
+                    if (interesting_cycles[i] == cycle) {
+                        sum += X * cycle;
+                    }
+                }
+
+                col++;
+                delay--;
+            }
+
+            X += add;
+
+            memset(buf, 0, BUFFER_SIZE);
+            p = buf;
+        }
+    }
+
+    printf("\n%i\n", sum);
+}