1 files changed, 31 insertions, 0 deletions
diff --git a/src/2020/day7/aoc.cpp b/src/2020/day7/aoc.cpp
index 2519be1..9ed0f99 100644
--- a/src/2020/day7/aoc.cpp
+++ b/src/2020/day7/aoc.cpp
@@ -1,4 +1,35 @@
 #include "aoc.h"
+#include <algorithm>
 
 namespace aoc2020 {
+
+bool find_color(color_bag* bag, line_view color) {
+  if (bag->color == color) {
+    return true;
+  } else {
+    for (auto& p : bag->bags) {
+      if (find_color(p.first, color)) {
+        return true;
+      }
+    }
+    return false;
+  }
+}
+
+int day7(line_view file, const char* color) {
+  bag_regulations rs;
+  per_line(file, [&rs](line_view lv) {
+    rs.parse(lv);
+    return true;
+  });
+
+  int total{0};
+  for (auto& b : rs.regulations) {
+    if (!(b.second->color == color)) {
+      total += int(find_color(b.second, color));
+    }
+  }
+
+  return total;
 }
+} // namespace aoc2020