1 files changed, 110 insertions, 1 deletions
diff --git a/src/2016/day11/aoc.cpp b/src/2016/day11/aoc.cpp
index 2381969..a3b0d63 100644
--- a/src/2016/day11/aoc.cpp
+++ b/src/2016/day11/aoc.cpp
@@ -1,6 +1,115 @@
 #include "aoc.h"
+#include <set>
+
+// F4 . .  .  .  .  .  .  .  .  .  .
+// F3 . .  .  .  .  .  .  HG HM RG RM
+// F2 . .  .  .  PM .  SM .  .  .  .
+// F1 E TG TM PG .  SG .  .  .  .  .
+//
+// F4 .  .  .  .  .
+// F3 .  .  .  LG .
+// F2 .  HG .  .  .
+// F1 E  .  HM .  LM
+//
+// 0.
+// take everythong to the forth floor
+//
+// 1.
+// there is an elevator that can move between the four floors.
+// When you enter the containment area, you and the elevator will start on the first floor.
+//
+// 2.
+// Its capacity rating means it can carry at most yourself and two RTGs or microchips in any combination.
+//
+// 3.
+// As a security measure, the elevator will only function if it contains at least one RTG or microchip.
+//
+// 4.
+// The elevator always stops on each floor to recharge,
+// Each elevator stop counts as one step, even if nothing is added to or removed from it
+//
+// 5.
+// if a chip is ever left in the same area as another RTG,
+// and it's not connected to its own RTG, the chip will be fried.
+//
 
 namespace aoc2016 {
 
-std::pair<int64_t, int64_t> day11(line_view) { return {0, 0}; }
+int next_floor(int f) {
+  static int df = 1;
+  if (f == 0)
+    df = 1;
+  if (f == 3)
+    df = -1;
+  return f + df;
+}
+
+struct rstatus {
+  ritem item;
+  bool matched = false;
+  bool fried = false;
+};
+
+static void check(size_t i, std::vector<rstatus>& rs) {
+  if (i < rs.size()) {
+    auto& r = rs[i];
+    if (!r.matched) {
+      for (size_t x = i + 1; x < rs.size(); x++) {
+        auto& r0 = rs[x];
+        if (r0.matched)
+          continue;
+        if (r.item.match(r0.item)) {
+          r.matched = true;
+          r0.matched = true;
+          break;
+        }
+        if (r.item.fried_with(r0.item)) {
+          r.fried = true;
+          r0.fried = true;
+        }
+      }
+    }
+    check(i + 1, rs);
+  }
+}
+
+bool isfine(const std::set<ritem>& rs) {
+  std::vector<rstatus> vs;
+  for (auto& r : rs) {
+    vs.emplace_back(r, false, false);
+  }
+  check(0, vs);
+  for (auto& s : vs) {
+    if (s.fried && !s.matched) {
+      return false;
+    }
+  }
+  return true;
+}
+
+bool isgood(const std::set<ritem>& rs) { // elevator
+  return rs.size() > 0 && rs.size() <= 2 && isfine(rs);
+}
+
+void setup_demo(std::vector<std::set<ritem>>& floors) {
+  std::set<ritem> f0 = {{chip, 0}, {chip, 1}};
+  std::set<ritem> f1 = {{gen, 0}};
+  std::set<ritem> f2 = {{gen, 1}};
+  std::set<ritem> f3 = {};
+  floors = {f0, f1, f2, f3};
+}
+
+void setup_input(std::vector<std::set<ritem>>& floors) {
+  std::set<ritem> f0 = {{chip, 0}, {gen, 0}, {gen, 1}, {gen, 2}};
+  std::set<ritem> f1 = {{chip, 1}, {chip, 2}};
+  std::set<ritem> f2 = {{chip, 3}, {gen, 3}, {chip, 4}, {gen, 4}};
+  std::set<ritem> f3 = {};
+  floors = {f0, f1, f2, f3};
+}
+
+std::pair<int64_t, int64_t> day11(line_view) {
+  std::vector<std::set<ritem>> floors;
+  setup_demo(floors);
+  return {0, 0};
+}
 } // namespace aoc2016