diff --git a/2022/puzzle-11-01.cc b/2022/puzzle-11-01.cc
new file mode 100644
index 0000000..77d804f
--- /dev/null
+++ b/2022/puzzle-11-01.cc
@@ -0,0 +1,203 @@
+//
+// Created by Matthew Gretton-Dann on 09/12/2022.
+//
+
+#include <array>
+#include <iostream>
+#include <list>
+#include <numeric>
+#include <string>
+#include <utility>
+#include <vector>
+
+using Int = std::int64_t;
+using UInt = std::uint64_t;
+
+enum class Op { undef, add, mult, dbl, square };
+
+struct Monkey
+{
+  auto add_item(UInt score) { items_.push_back(score); }
+  auto op(Op op)
+  {
+    assert(op == Op::dbl || op == Op::square);
+    op_ = op;
+  }
+  auto op(Op op, UInt amt)
+  {
+    assert(op == Op::add || op == Op::mult);
+    op_ = op;
+    amt_ = amt;
+  }
+  auto test(UInt test) { test_ = test; }
+  auto true_monkey(UInt monkey) { true_monkey_ = monkey; }
+  auto false_monkey(UInt monkey) { false_monkey_ = monkey; }
+
+  [[nodiscard]] auto process_front() -> std::pair<UInt, UInt>
+  {
+    auto item{items_.front()};
+    items_.pop_front();
+    switch (op_) {
+    case Op::square:
+      item *= item;
+      break;
+    case Op::dbl:
+      item += item;
+      break;
+    case Op::add:
+      item += amt_;
+      break;
+    case Op::mult:
+      item *= amt_;
+      break;
+    default:
+      std::cerr << "Unexpected op\n";
+      std::abort();
+    }
+    item /= 3;
+    UInt const monkey{(item % test_ == 0) ? true_monkey_ : false_monkey_};
+    ++inspection_count_;
+    return std::make_pair(item, monkey);
+  }
+
+  [[nodiscard]] auto empty() const -> bool { return items_.empty(); }
+
+  [[nodiscard]] auto score() const -> UInt { return inspection_count_; }
+
+private:
+  std::list<UInt> items_;
+  Op op_{Op::undef};
+  UInt amt_{0};
+  UInt test_{0};
+  UInt true_monkey_{std::numeric_limits<Int>::max()};
+  UInt false_monkey_{std::numeric_limits<Int>::max()};
+  UInt inspection_count_{0};
+};
+
+struct State
+{
+  auto populate(std::istream& is) -> bool
+  {
+    using namespace std::literals::string_literals;
+
+    std::string line;
+    auto it{monkies_.end()};
+    while (std::getline(is, line)) {
+      if (line.empty()) {
+        continue;
+      }
+      if (line.substr(0, 7) == "Monkey "s) {
+        it = monkies_.insert(monkies_.end(), Monkey{});
+      }
+      else if (line.substr(0, 18) == "  Starting items: "s) {
+        assert(it != monkies_.end());
+        std::size_t pos{18};
+        while (pos < line.size()) {
+          if (line[pos] == ' ' || line[pos] == ',') {
+            ++pos;
+          }
+          else if (std::isdigit(line[pos]) != 0) {
+            std::size_t len{0};
+            it->add_item(std::stoull(line.substr(pos), &len));
+            pos += len;
+          }
+          else {
+            std::cerr << "Unable to interpret: " << line << '\n';
+            return false;
+          }
+        }
+      }
+      else if (line.substr(0, 23) == "  Operation: new = old "s) {
+        assert(it != monkies_.end());
+
+        if (line[23] == '+') {
+          if (line.substr(25) == "old") {
+            it->op(Op::dbl);
+          }
+          else {
+            it->op(Op::add, std::stoull(line.substr(25)));
+          }
+        }
+        else {
+          if (line[23] != '*') {
+            std::cerr << "Unable to interpret: " << line << '\n';
+            return false;
+          }
+          if (line.substr(25) == "old") {
+            it->op(Op::square);
+          }
+          else {
+            it->op(Op::mult, std::stoull(line.substr(25)));
+          }
+        }
+      }
+      else if (line.substr(0, 21) == "  Test: divisible by "s) {
+        assert(it != monkies_.end());
+
+        it->test(std::stoull(line.substr(21)));
+      }
+      else if (line.substr(0, 29) == "    If true: throw to monkey "s) {
+        assert(it != monkies_.end());
+
+        it->true_monkey(std::stoull(line.substr(29)));
+      }
+      else if (line.substr(0, 30) == "    If false: throw to monkey "s) {
+        assert(it != monkies_.end());
+
+        it->false_monkey(std::stoull(line.substr(30)));
+      }
+      else {
+        std::cerr << "Unable to interpret: " << line << '\n';
+        return false;
+      }
+    }
+    return true;
+  }
+
+  auto run_round()
+  {
+    unsigned m{0};
+    for (auto& monkey : monkies_) {
+      std::cout << "Monkey: " << m++ << '\n';
+      while (!monkey.empty()) {
+        auto [item, dest] = monkey.process_front();
+        std::cout << "  Moving " << item << " to " << dest << '\n';
+        monkies_[dest].add_item(item);
+      }
+    }
+  }
+
+  [[nodiscard]] auto score() const -> UInt
+  {
+    UInt max1{0};
+    UInt max2{0};
+    for (auto const& monkey : monkies_) {
+      if (monkey.score() >= max1) {
+        max2 = max1;
+        max1 = monkey.score();
+      }
+      else if (monkey.score() >= max2) {
+        max2 = monkey.score();
+      }
+    }
+
+    std::cout << "Max score = " << max1 << " *  " << max2 << " = " << max1 * max2 << "\n";
+    return max1 * max2;
+  }
+
+  std::vector<Monkey> monkies_;
+};
+
+auto main() -> int
+{
+  State state;
+
+  if (!state.populate(std::cin)) {
+    return EXIT_FAILURE;
+  }
+  for (UInt i = 0; i < 20; ++i) {
+    state.run_round();
+  }
+  std::cout << "Score: " << state.score() << '\n';
+  return 0;
+}
diff --git a/2022/puzzle-11-02.cc b/2022/puzzle-11-02.cc
new file mode 100644
index 0000000..eb784a6
--- /dev/null
+++ b/2022/puzzle-11-02.cc
@@ -0,0 +1,208 @@
+//
+// Created by Matthew Gretton-Dann on 09/12/2022.
+//
+
+#include <array>
+#include <cassert>
+#include <iostream>
+#include <list>
+#include <numeric>
+#include <string>
+#include <utility>
+#include <vector>
+
+using Int = std::int64_t;
+using UInt = std::uint64_t;
+
+enum class Op { undef, add, mult, dbl, square };
+
+struct Monkey
+{
+  auto add_item(UInt score) { items_.push_back(score); }
+  auto op(Op op)
+  {
+    assert(op == Op::dbl || op == Op::square);
+    op_ = op;
+  }
+  auto op(Op op, UInt amt)
+  {
+    assert(op == Op::add || op == Op::mult);
+    op_ = op;
+    amt_ = amt;
+  }
+  auto test(UInt test) { test_ = test; }
+  auto true_monkey(UInt monkey) { true_monkey_ = monkey; }
+  auto false_monkey(UInt monkey) { false_monkey_ = monkey; }
+
+  [[nodiscard]] auto process_front() -> std::pair<UInt, UInt>
+  {
+    auto item{items_.front()};
+    auto const max{std::numeric_limits<UInt>::max()};
+    items_.pop_front();
+    switch (op_) {
+    case Op::square:
+      assert(item < (max / item));
+      item *= item;
+      break;
+    case Op::dbl:
+      assert(item < (max - item));
+      item += item;
+      break;
+    case Op::add:
+      assert(item < (max - amt_));
+      item += amt_;
+      break;
+    case Op::mult:
+      assert(item < (max / amt_));
+      item *= amt_;
+      break;
+    default:
+      std::cerr << "Unexpected op\n";
+      std::abort();
+    }
+    UInt const monkey{(item % test_ == 0) ? true_monkey_ : false_monkey_};
+    ++inspection_count_;
+    return std::make_pair(item, monkey);
+  }
+
+  [[nodiscard]] auto empty() const -> bool { return items_.empty(); }
+
+  [[nodiscard]] auto score() const -> UInt { return inspection_count_; }
+
+private:
+  std::list<UInt> items_;
+  Op op_{Op::undef};
+  UInt amt_{0};
+  UInt test_{0};
+  UInt true_monkey_{std::numeric_limits<Int>::max()};
+  UInt false_monkey_{std::numeric_limits<Int>::max()};
+  UInt inspection_count_{0};
+};
+
+struct State
+{
+  auto populate(std::istream& is) -> bool
+  {
+    using namespace std::literals::string_literals;
+
+    std::string line;
+    auto it{monkies_.end()};
+    while (std::getline(is, line)) {
+      if (line.empty()) {
+        continue;
+      }
+      if (line.substr(0, 7) == "Monkey "s) {
+        it = monkies_.insert(monkies_.end(), Monkey{});
+      }
+      else if (line.substr(0, 18) == "  Starting items: "s) {
+        assert(it != monkies_.end());
+        std::size_t pos{18};
+        while (pos < line.size()) {
+          if (line[pos] == ' ' || line[pos] == ',') {
+            ++pos;
+          }
+          else if (std::isdigit(line[pos]) != 0) {
+            std::size_t len{0};
+            it->add_item(std::stoull(line.substr(pos), &len));
+            pos += len;
+          }
+          else {
+            std::cerr << "Unable to interpret: " << line << '\n';
+            return false;
+          }
+        }
+      }
+      else if (line.substr(0, 23) == "  Operation: new = old "s) {
+        assert(it != monkies_.end());
+
+        if (line[23] == '+') {
+          if (line.substr(25) == "old") {
+            it->op(Op::dbl);
+          }
+          else {
+            it->op(Op::add, std::stoull(line.substr(25)));
+          }
+        }
+        else {
+          if (line[23] != '*') {
+            std::cerr << "Unable to interpret: " << line << '\n';
+            return false;
+          }
+          if (line.substr(25) == "old") {
+            it->op(Op::square);
+          }
+          else {
+            it->op(Op::mult, std::stoull(line.substr(25)));
+          }
+        }
+      }
+      else if (line.substr(0, 21) == "  Test: divisible by "s) {
+        assert(it != monkies_.end());
+        auto div{std::stoull(line.substr(21))};
+
+        it->test(div);
+        mod_ *= div;
+      }
+      else if (line.substr(0, 29) == "    If true: throw to monkey "s) {
+        assert(it != monkies_.end());
+
+        it->true_monkey(std::stoull(line.substr(29)));
+      }
+      else if (line.substr(0, 30) == "    If false: throw to monkey "s) {
+        assert(it != monkies_.end());
+
+        it->false_monkey(std::stoull(line.substr(30)));
+      }
+      else {
+        std::cerr << "Unable to interpret: " << line << '\n';
+        return false;
+      }
+    }
+    return true;
+  }
+
+  auto run_round()
+  {
+    for (auto& monkey : monkies_) {
+      while (!monkey.empty()) {
+        auto [item, dest] = monkey.process_front();
+        monkies_[dest].add_item(item % mod_);
+      }
+    }
+  }
+
+  [[nodiscard]] auto score() const -> UInt
+  {
+    UInt max1{0};
+    UInt max2{0};
+    for (auto const& monkey : monkies_) {
+      if (monkey.score() >= max1) {
+        max2 = max1;
+        max1 = monkey.score();
+      }
+      else if (monkey.score() >= max2) {
+        max2 = monkey.score();
+      }
+    }
+
+    std::cout << "Max score = " << max1 << " *  " << max2 << " = " << max1 * max2 << "\n";
+    return max1 * max2;
+  }
+
+  std::vector<Monkey> monkies_;
+  UInt mod_{1};
+};
+
+auto main() -> int
+{
+  State state;
+
+  if (!state.populate(std::cin)) {
+    return EXIT_FAILURE;
+  }
+  for (UInt i = 0; i < 10'000; ++i) {
+    state.run_round();
+  }
+  std::cout << "Score: " << state.score() << '\n';
+  return 0;
+}