traverse lap

1 files changed, 33 insertions, 3 deletions

diff --git a/src/2018/day6/aoc.cpp b/src/2018/day6/aoc.cpp
index 5350b0e..07f8ad9 100644
--- a/src/2018/day6/aoc.cpp
+++ b/src/2018/day6/aoc.cpp
@@ -26,10 +26,40 @@ int day6(line_view file) {
     p.distance = 0;
 
     std::vector<int> total = {0};
-    c.traverse([&total, &b, &c](int lap, int dir, coordinate x) { return true; },
-               [&total]() { return total[total.size() - 1] == 0; });
+
+    auto f = [&total, &b, &c, &i](size_t lap, coordinate x) {
+      if (x.x >= 0 && x.x <= b.cols && x.y >= 0 && x.y <= b.rows) {
+        if (lap == total.size()) {
+          total.push_back(0);
+        }
+        auto& p = b.ps[x.y * b.rows + x.x];
+        int d = x.distance(c);
+        if (d < p.distance) {
+          p.id = i;
+          p.distance = d;
+          total[lap] += 1;
+        }
+        if (d == p.distance) {
+          p.id = -2; // same distance
+          total[lap] += 1;
+        }
+      }
+      return true;
+    };
+    auto g = [&total]() { return total[total.size() - 1] == 0; };
+    c.traverse(f, g);
+  }
+
+  std::vector<int> xs(cs.size(), 0);
+  b.count(xs);
+
+  int max{INT32_MIN};
+  for (auto& x : xs) {
+    if (x != INT32_MAX && x > max) {
+      max = x;
+    }
   }
-  return 0;
+  return max;
 }
 
 } // namespace aoc2018