1 files changed, 59 insertions, 1 deletions
diff --git a/src/2018/day3/aoc.h b/src/2018/day3/aoc.h
index 4bfdbf3..24fad47 100644
--- a/src/2018/day3/aoc.h
+++ b/src/2018/day3/aoc.h
@@ -1,6 +1,64 @@
 #pragma once
 #include "common.h"
+#include <vector>
 
 namespace aoc2018 {
 
-}
+struct claim {
+  int id;
+  int x;
+  int y;
+  int width;
+  int height;
+};
+
+struct fabric {
+  // 0 ... 999
+  uint16_t claims[1000 * 1000] = {0};
+
+  void apply(const claim& c) {
+    for (int x = c.x; x < c.x + c.width; x++) {
+      for (int y = c.y; y < c.y + c.height; y++) {
+        claims[y * 1000 + x] += 1;
+      }
+    }
+  }
+
+  int count(int x) {
+    int total{0};
+    for (auto c : claims) {
+      if (c > x) {
+        total += 1;
+      }
+    }
+    return total;
+  }
+
+  void get_number(const char** pp, int* is[], int i) {
+    *is[i] = 0;
+    const char* p = *pp;
+    while (*p >= '0' && *p <= '9') {
+      *is[i] = *is[i] * 10 + *p - '0';
+      p++;
+    }
+    *pp = p;
+  }
+
+  void parse(line_view lv) {
+    claim c;
+    int* is[] = {&c.id, &c.x, &c.y, &c.width, &c.height};
+    int i{0};
+    const char* p = lv.line;
+    while (p < lv.line + lv.length) {
+      if (*p >= '0' && *p <= '9') {
+        get_number(&p, is, i++);
+      }
+      p++;
+    }
+    apply(c);
+  }
+};
+
+int day3(line_view, int);
+
+} // namespace aoc2018