diff --git a/dat/24/ex/17.txt b/dat/24/ex/17a.txt
similarity index 100%
rename from dat/24/ex/17.txt
rename to dat/24/ex/17a.txt
diff --git a/dat/24/ex/17b.txt b/dat/24/ex/17b.txt
new file mode 100644
index 0000000..f69bbc0
--- /dev/null
+++ b/dat/24/ex/17b.txt
@@ -0,0 +1,5 @@
+Register A: 117440
+Register B: 0
+Register C: 0
+
+Program: 0,3,5,4,3,0
diff --git a/sol/24/CMakeLists.txt b/sol/24/CMakeLists.txt
index 41ccd9c..787c216 100644
--- a/sol/24/CMakeLists.txt
+++ b/sol/24/CMakeLists.txt
@@ -15,7 +15,7 @@ set(SOURCES
     "day10.cpp"
     # "day11.cpp"
     "day14.cpp"
-    "day16.cpp"
+    # "day16.cpp"
     "day17.cpp"
 )
 add_library(aoc24 STATIC ${HEADERS} ${SOURCES})
diff --git a/sol/24/aoc.cpp b/sol/24/aoc.cpp
index 84ef906..ec4fc9b 100644
--- a/sol/24/aoc.cpp
+++ b/sol/24/aoc.cpp
@@ -30,7 +30,7 @@ auto entry([[maybe_unused]]std::span<char const*> const& args) -> std::expected<
     case 10: return day10(args);
     // case 11: return day11(args);
     case 14: return day14(args);
-    case 16: return day16(args);
+    // case 16: return day16(args);
     case 17: return day17(args);
     default:
         return aoc::make_error(fmt::format("day {}", day), std::errc::not_supported);
diff --git a/sol/24/day16.cpp b/sol/24/day16.cpp
index 813ab73..70360af 100644
--- a/sol/24/day16.cpp
+++ b/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> {
diff --git a/sol/24/day17.cpp b/sol/24/day17.cpp
index 0065409..af909b0 100644
--- a/sol/24/day17.cpp
+++ b/sol/24/day17.cpp
@@ -2,6 +2,7 @@
 #include <ranges>
 #include <numeric>
 #include <memory>
+#include <iostream>
 
 #include "aoc.hpp"
 #include "aoc/utils.hpp"
@@ -14,15 +15,15 @@ using namespace std::string_view_literals;
 
 namespace uec {
 enum class opcode : u16 {
-    adv,
-    bxl,
-    bst,
-    jnz,
-    bxc,
-    out,
-    bdv,
-    cdv,
-    nop,
+    adv = 0,
+    bxl = 1,
+    bst = 2,
+    jnz = 3,
+    bxc = 4,
+    out = 5,
+    bdv = 6,
+    cdv = 7,
+    nop = 8,
 };
 
 auto opcode_to_str(opcode op) -> char const* {
@@ -59,18 +60,25 @@ public:
 
     auto clock() -> void {
         auto const op = read();
+        if (peek() == opcode::nop) return;
 
+        auto const x = combo();
         switch (op) {
-        case opcode::adv: adv();
-        case opcode::bxl: bxl();
-        case opcode::bst: bst();
-        case opcode::jnz: jnz();
-        case opcode::bxc: bxc();
-        case opcode::out: out();
-        case opcode::bdv: bdv();
-        case opcode::cdv: cdv();
-        default: nop();
+            case opcode::adv: adv(x); break;
+            case opcode::bxl: bxl();  break;
+            case opcode::bst: bst(x); break;
+            case opcode::jnz: jnz();  break;
+            case opcode::bxc: bxc();  break;
+            case opcode::out: out(x); break;
+            case opcode::bdv: bdv(x); break;
+            case opcode::cdv: cdv(x); break;
+            default: nop(); break;
         }
+        m_pc += 2;
+    }
+
+    auto halt() const -> bool {
+        return peek() == opcode::nop;
     }
 
     auto str() const -> std::string {
@@ -86,10 +94,42 @@ public:
 
         for (usize i = 0; i < m_program.size(); ++i) {
             str += fmt::format("{:02x}: ", i);
-            str += fmt::format("{}\n", opcode_to_str(m_program[i]));
+            str += fmt::format("{}{}\n", opcode_to_str(m_program[i]), m_pc == i ? " <" : "");
+        }
+        str += "\n";
+
+        str += "       ";
+        for (usize i = 0; i < 16; ++i) {
+           str += fmt::format("{:02X}", i);
+           if (i == 7) str += "  ";
+           else str += " ";
+        }
+        str += "\n\n";
+
+        for (usize i = 0; i < m_output.size() * sizeof(u64); ++i) {
+           if (i % 16 == 0) str += fmt::format("{:04X}:  ", i);
+           str += fmt::format("{:02X}", *(reinterpret_cast<u8*>(const_cast<u64*>(m_output.data())) + i));
+           if ((i + 1) % 16 == 0) str += "\n";
+           else if ((i + 1) % 8 == 0) str += "  ";
+           else str += " ";
+        }
+        if (m_output.size() != 0)
+           str += "\n";
+
+        str += "-------------------------------------------------------\n";
+        return str;
+    }
+
+    auto output_str() const -> std::string {
+        std::string str{};
+        for (usize i = 0; i < m_output.size(); ++i) {
+            str += fmt::format("{}", m_output.at(i));
+            if (i < m_output.size() - 1) str += ",";
         }
         return str;
     }
+    auto output() const -> std::vector<u64> const& { return m_output; }
+
 
 private:
     auto read() const -> opcode {
@@ -102,9 +142,13 @@ private:
             return m_program[m_pc + 1];
         return opcode::nop;
     }
-
     auto combo() const -> u64 {
-        return 0;
+        auto const op = u64(peek());
+        if (op < 4) return op;
+        else if (op == 4) return m_regs.a;
+        else if (op == 5) return m_regs.b;
+        else if (op == 6) return m_regs.c;
+        else return u64(opcode::nop);
     }
 
 private:
@@ -112,34 +156,54 @@ private:
         m_regs.a >>= x;
     }
     auto bxl() -> void {
-        m_regs.b = m_regs.b ^ u64(opcode::bxl);
+        m_regs.b = m_regs.b ^ u64(peek());
     }
     auto bst(u64 x) -> void {
         m_regs.b = x % 8;
     }
     auto jnz() -> void {
-        if (m_regs.a == 0) return;
-        m_pc = u64(opcode::jnz);
+        if (m_regs.a == 0)
+            return;
+        m_pc = u64(peek()) - 2;
     }
     auto bxc() -> void {
         m_regs.b = m_regs.b ^ m_regs.c;
     }
     auto out(u64 x) -> void {
-
+        m_output.emplace_back(x % 8);
+    }
+    auto bdv(u64 x) -> void {
+        m_regs.b = m_regs.a >> x;
+    }
+    auto cdv(u64 x) -> void {
+        m_regs.c = m_regs.a >> x;
     }
-    auto bdv() -> void {}
-    auto cdv() -> void {}
     auto nop() -> void {}
 
 private:
     u64 m_pc{};
     uec::regs m_regs{};
     std::vector<opcode> m_program{};
+    std::vector<u64> m_output{};
 };
 }
 
+auto part_a(uec::regs const& regs, std::vector<uec::opcode> const& program) -> void {
+    uec::cpu cpu{};
+    cpu.load(regs, program);
+
+    while (!cpu.halt()) {
+        // fmt::print("{}", cpu.str());
+        // std::cin.get();
+        cpu.clock();
+    }
+    fmt::print("{}", cpu.str());
+    fmt::print("{}\n", cpu.output_str());
+}
+
 auto aoc24::day17([[maybe_unused]]std::span<char const*> const& args) -> std::expected<void, aoc::error> {
-    auto res = aoc::read_text("./dat/24/ex/17.txt");
+    // auto res = aoc::read_text("./dat/24/ex/17a.txt");
+    auto res = aoc::read_text("./dat/24/ex/17b.txt");
     // auto res = aoc::read_text("./dat/24/re/17.txt");
     if (!res) return std::unexpected(res.error());
     auto const txt = *res;
@@ -174,10 +238,10 @@ auto aoc24::day17([[maybe_unused]]std::span<char const*> const& args) -> std::ex
         }
     }
 
-    uec::cpu cpu{};
-    cpu.load(regs, program);
+    // part_a(regs, program);
 
-    fmt::print("{}", cpu.str());
+    uec::cpu cpu{};
+    cpu.load({}, program);
 
     return {};
 }