2020 day5

1 files changed, 33 insertions, 0 deletions

diff --git a/src/2020/day5/aoc.cpp b/src/2020/day5/aoc.cpp
index 849bad9..2ea306a 100644
--- a/src/2020/day5/aoc.cpp
+++ b/src/2020/day5/aoc.cpp
@@ -1,5 +1,38 @@
 #include "aoc.h"
+#include <algorithm>
+#include <vector>
 
 namespace aoc2020 {
 
+// row 0 - 127
+// col 0 - 7
+static void missing(const std::vector<seat>& seats, std::vector<seat>& miss) {
+  static int plane[128 * 8] = {0};
+  for (auto& s : seats) {
+    plane[8 * s.row + s.col] = 1;
+  }
+  for (size_t i = 0; i < ARRAY_SIZE(plane); i++) {
+    if (plane[i] == 0) {
+      int r = i / 8;
+      int c = i % 8;
+      if (r != 0 && r != 127) {
+        miss.emplace_back(seat{r, c});
+      }
+    }
+  }
 }
+
+int day5(line_view file) {
+  std::vector<seat> seats;
+  per_line(file, [&seats](line_view lv) {
+    seats.emplace_back(lv);
+    return true;
+  });
+  std::vector<seat> miss;
+  missing(seats, miss);
+  // std::for_each(miss.begin(), miss.end(), [](const seat& s) { printf("%d %d %d\n", s.row, s.col, s.id()); });
+  std::sort(seats.begin(), seats.end());
+  return seats[seats.size() - 1].id();
+}
+
+} // namespace aoc2020