2022 day10

1 files changed, 104 insertions, 1 deletions

diff --git a/src/2022/day10/aoc.cpp b/src/2022/day10/aoc.cpp
index 58b89e4..b076561 100644
--- a/src/2022/day10/aoc.cpp
+++ b/src/2022/day10/aoc.cpp
@@ -1,10 +1,113 @@
 #include "aoc.h"
+#include <functional>
+#include <string.h>
 
 namespace aoc2022 {
 
+static int X = 1;
+static int cycles = 1;
+
+static int get_number(const char *p) {
+  int sign = *p == '-' ? -1 : 1;
+  if (sign == -1) p++;
+  int d{0};
+  while(*p >= '0' && *p <= '9') {
+    d = d * 10 + *p - '0';
+    p++;
+  }
+  return sign * d;
+}
+
+struct CP {
+  int d{0};
+  bool done = false;
+
+  CP(int x): d(x) {}
+};
+
+void point(int d, CP cp[], int* total) {
+  // printf("cycle %d X %d\n", d, X);
+  for (int i = 0; i < 6; i++) {
+    if (!cp[i].done && cp[i].d == d) {
+      *total += X * d;
+      // printf("%d: %d = %d\n", d, X, X * d);
+      cp[i].done = true;
+      break;
+    }
+  }
+}
+
+// static void print(char p[]) {
+//   for(int i = 0; i < 240; i++) {
+//     printf("%c", p[i]);
+//     if ((i+1) % 40 == 0) {
+//       printf("\n");
+//     }
+//   }
+// }
+
+static void draw(int i, char crt[], char c) {
+  crt[i - 1] = c; 
+}
+
+static void reset(char crt[]) {
+  for (int i = 0; i < 240; i++) {
+     * (crt + i) = '.';
+  }
+}
+
+static void set(char crt[], int x) {
+  reset(crt);
+  crt[x] = '#';
+  crt[x+1] = '#';
+  crt[x+2] = '#';
+}
+
 std::pair<int, int> day10(line_view file) 
 { 
-  return {0, 0};
+
+  char screen[240] = {0};
+  char sprite[240] = {0};
+  reset(screen);
+  set(sprite, X);
+
+  struct {
+    const char *cmd;
+    std::function<void(const char*, CP [], int*, char [])> f;
+  } cmds[] = {
+    {"addx", [&sprite](const char* p, CP cp[], int* total, char crt[]){
+      auto d = get_number(p);
+      point(cycles, cp, total);
+      draw(cycles, crt, sprite[cycles % 40]);
+      cycles += 1; 
+      point(cycles, cp, total);
+      draw(cycles, crt, sprite[cycles % 40]);
+      cycles += 1; 
+      X += d;
+      set(sprite, X);
+    }},
+    {"noop", [&sprite](const char* p, CP cp[], int* total, char crt[]){
+      // printf("noop\n");
+      point(cycles, cp, total);
+      draw(cycles, crt, sprite[cycles % 40]);
+      cycles += 1;
+    }},
+  };
+
+  CP cp[] = {20, 60, 100, 140, 180, 220};
+  int total{0};
+  per_line(file, [&cmds, &cp, &total, &screen](line_view lv) {
+     for(auto &c: cmds)  {
+        if (strncmp(c.cmd, lv.line, 4) == 0) {
+            c.f(lv.line+5, cp, &total, screen);
+            break;
+        }
+     }
+     return true;
+  });
+
+  // print(screen);
+  return {total, 0};
 }
 
 } // namespace aoc2022