2016 day24 part1

1 files changed, 75 insertions, 1 deletions

diff --git a/src/2016/day24/aoc.cpp b/src/2016/day24/aoc.cpp
index 3a5dc38..6642db2 100644
--- a/src/2016/day24/aoc.cpp
+++ b/src/2016/day24/aoc.cpp
@@ -1,6 +1,80 @@
 #include "aoc.h"
+#include <deque>
+#include <map>
 
 namespace aoc2016 {
 
-std::pair<int64_t, int64_t> day24(line_view) { return {0, 0}; }
+void bfs(maze::pos p, maze& m, std::map<maze::pos, int>& ds) {
+  ds.insert({p, 0});
+  std::deque<maze::pos> q;
+  q.push_back(p);
+
+  while (!q.empty()) {
+    auto s = q.size();
+    while (s-- > 0) {
+      maze::pos p0 = q.front();
+      q.pop_front();
+
+      maze::pos ns[4] = {
+          {p0.x - 1, p0.y},
+          {p0.x + 1, p0.y},
+          {p0.x, p0.y - 1},
+          {p0.x, p0.y + 1},
+      };
+      auto& d = ds[p0];
+      for (auto& n : ns) {
+        if (m.get(n.x, n.y) != '#') {
+          auto px = ds.insert({n, d + 1});
+          if (px.second) {
+            q.push_back(n);
+          }
+          if (!px.second && px.first->second > d + 1) {
+            px.first->second = d + 1;
+            q.push_back(n);
+          }
+        }
+      }
+    }
+  }
+
+  auto& ns = m.numbers;
+  for (auto it = ds.begin(); it != ds.end();) {
+    if (ns.find(it->first) == ns.end()) {
+      it = ds.erase(it);
+    } else {
+      it++;
+    }
+  }
+}
+
+std::pair<int64_t, int64_t> day24(line_view file) {
+  // maze mz{179, 43}; // input
+  maze mz{11, 5}; // demo
+  int r{0};
+  per_line(file, [&r, &mz](line_view lv) {
+    mz.load(r++, lv);
+    return true;
+  });
+
+  std::vector<std::map<maze::pos, int>> vds;
+  vds.resize(5); // demo
+  for (auto &n: mz.numbers) {
+    int i = mz.get(n.x, n.y) - '0';
+    auto& ds = vds[i];
+    bfs(n, mz, ds);
+  }
+
+  // for (auto& ds : vds) {
+  //   for (auto& kv : ds) {
+  //     printf("(%c: %d) ", mz.get(kv.first.x, kv.first.y), kv.second);
+  //   }
+  //   printf("\n");
+  // }
+
+  // mz.print();
+  // for (auto& p : mz.numbers) {
+  //   printf("%c: (%d, %d)\n", mz.get(p.x, p.y), p.x, p.y);
+  // }
+  return {0, 0};
+}
 } // namespace aoc2016