aoc: 2024 bk

sol/24/day16.cpp

@@ -2,6 +2,8 @@
 #include <ranges>
 #include <numeric>
 #include <memory>
+#include <map>
+#include <queue>
 
 #include "aoc.hpp"
 #include "aoc/utils.hpp"
@@ -18,7 +20,7 @@ struct edge {
 
     auto str() const -> std::string {
         if (b == 0) return "nil";
-        return fmt::format("{},{}", (b >> 32), b & 0xFFFFFFFF);
+        return fmt::format("{}.{}", (b >> 32), b & 0xFFFFFFFF);
     }
 };
 
@@ -31,20 +33,21 @@ struct node {
 
     auto str() const -> std::string {
         std::string str{"node {"};
-        str += " id: " + fmt::format("{},{}", (id >> 32) & 0xFFFFFFFF, id & 0xFFFFFFFF) + ",";
+        str += " id: " + fmt::format("{}.{}", (id >> 32) & 0xFFFFFFFF, id & 0xFFFFFFFF);
         if (n.b != 0)
-            str += " n -> " + n.str() + ",";
+            str += ", n → " + n.str();
         if (s.b != 0)
-            str += " s -> " + s.str() + ",";
+            str += ", s → " + s.str();
         if (e.b != 0)
-            str += " e -> " + e.str() + ",";
+            str += ", e → " + e.str();
         if (w.b != 0)
-            str += " w -> " + w.str();
+            str += ", w → " + w.str();
         str += " }";
         return str;
     }
 };
 
+
 class graph {
 public:
     graph(std::string const& maze_str) : m_start(0), m_exit(0) {
@@ -55,6 +58,8 @@ public:
         }
     }
 
+    auto vertices() const -> std::vector<node> const& { return m_nodes; }
+
 private:
     auto build(std::string const& maze) -> void {
         auto const lines = maze | aoc::split("\n"sv)
@@ -83,7 +88,7 @@ private:
                 if (n_e != '#') {
                     n.n = {
                         .a = n.id,
-                        .b = u64((u64(i - 2) << 32) | (j + 1))
+                        .b = u64((u64(i) << 32) | (j + 1))
                     };
                     m_edges.emplace_back(n.n);
                 }
@@ -97,7 +102,7 @@ private:
                 if (e_e != '#') {
                     n.e = {
                         .a = n.id,
-                        .b = u64((u64(i + 1) << 32) | (j - 2))
+                        .b = u64((u64(i + 1) << 32) | (j))
                     };
                     m_edges.emplace_back(n.e);
                 }
@@ -122,6 +127,30 @@ private:
     u64 m_rows{};
     u64 m_cols{};
 };
+
+// auto dfs() -> void {}
+// auto bfs() -> void {}
+
+auto dijkstra(graph const& g, u64 source) -> void {
+    std::map<u64, i64> dist{};
+    std::map<u64, i64> prev{};
+    for (auto const& v : g.vertices()) {
+        dist.insert({v.id, aoc::lim<i64>::max()});
+        prev.insert({v.id, -1});
+    }
+    dist[source] = 0;
+    std::queue<node> q{};
+    q.push(g.vertices()[0]);
+
+    while (!q.empty()) {
+        node u = q.pop();
+
+        if (u.n.b != 0) {
+            i64 alt = dist[u.id] == aoc::lim<i64>::max() ? 1 : dist[u.id] + 1;
+        }
+    }
+}
+
 }
 
 auto aoc24::day16([[maybe_unused]]std::span<char const*> const& args) -> std::expected<void, aoc::error> {