Add Puzzles for 2022 day 13

2022/puzzle-13-01.cc

@@ -0,0 +1,110 @@
+//
+// Created by Matthew Gretton-Dann on 09/12/2022.
+//
+
+#include <array>
+#include <iostream>
+#include <numeric>
+#include <string>
+#include <utility>
+
+using Int = std::int64_t;
+using UInt = std::uint64_t;
+
+auto ordered(std::string const& left, std::string const& right) noexcept -> bool
+{
+  auto left_it{left.begin()};
+  auto right_it{right.begin()};
+  UInt left_depth{0};
+  UInt right_depth{0};
+
+  while (left_it != left.end() && right_it != right.end()) {
+    while (left_it != left.end() && *left_it == '[') {
+      ++left_depth;
+      ++left_it;
+    }
+    while (right_it != right.end() && *right_it == '[') {
+      ++right_depth;
+      ++right_it;
+    }
+    std::size_t left_pos{0};
+    std::size_t right_pos{0};
+    UInt left_num{0};
+    UInt right_num{0};
+    if (left_it != left.end() && std::isdigit(*left_it) != 0) {
+      left_num = std::stoull(left.substr(left_it - left.begin()), &left_pos);
+    }
+    if (right_it != right.end() && std::isdigit(*right_it) != 0) {
+      right_num = std::stoull(right.substr(right_it - right.begin()), &right_pos);
+    }
+    left_it += static_cast<std::string::difference_type>(left_pos);
+    right_it += static_cast<std::string::difference_type>(right_pos);
+    if (right_pos == 0) {
+      if (left_pos != 0) {
+        return false;
+      }
+      if (left_depth < right_depth) {
+        return true;
+      }
+      if (right_depth > left_depth) {
+        return false;
+      }
+    }
+    else if (left_pos == 0) {
+      return true;
+    }
+    if (right_num < left_num) {
+      return false;
+    }
+    if (left_num < right_num) {
+      return true;
+    }
+
+    while (left_it != left.end() && *left_it == ']') {
+      --left_depth;
+      ++left_it;
+    }
+    while (right_it != right.end() && *right_it == ']') {
+      --right_depth;
+      ++right_it;
+    }
+    if (left_depth != right_depth) {
+      return left_depth < right_depth;
+    }
+    if (left_it != left.end() && *left_it == ',') {
+      ++left_it;
+    }
+    if (right_it != left.end() && *right_it == ',') {
+      ++right_it;
+    }
+  }
+
+  return left_it == left.end();
+}
+
+auto main() -> int
+{
+  std::string line;
+
+  std::string left;
+  UInt idx{1};
+  UInt score{0};
+  while (std::getline(std::cin, line)) {
+    if (line.empty()) {
+      continue;
+    }
+    if (left.empty()) {
+      left = line;
+    }
+    else {
+      if (ordered(left, line)) {
+        std::cout << left << " < " << line << '\n';
+        score += idx;
+      }
+      ++idx;
+      left.clear();
+    }
+  }
+  std::cout << "Score: " << score << '\n';
+  return 0;
+}

2022/puzzle-13-02.cc

@@ -0,0 +1,116 @@
+//
+// Created by Matthew Gretton-Dann on 09/12/2022.
+//
+
+#include <array>
+#include <iostream>
+#include <set>
+#include <string>
+#include <utility>
+
+using Int = std::int64_t;
+using UInt = std::uint64_t;
+
+struct Ordering
+{
+  auto operator()(std::string const& left, std::string const& right) const noexcept -> bool
+  {
+    auto left_it{left.begin()};
+    auto right_it{right.begin()};
+    UInt left_depth{0};
+    UInt right_depth{0};
+
+    while (left_it != left.end() && right_it != right.end()) {
+      while (left_it != left.end() && *left_it == '[') {
+        ++left_depth;
+        ++left_it;
+      }
+      while (right_it != right.end() && *right_it == '[') {
+        ++right_depth;
+        ++right_it;
+      }
+      std::size_t left_pos{0};
+      std::size_t right_pos{0};
+      UInt left_num{0};
+      UInt right_num{0};
+      if (left_it != left.end() && std::isdigit(*left_it) != 0) {
+        left_num = std::stoull(left.substr(left_it - left.begin()), &left_pos);
+      }
+      if (right_it != right.end() && std::isdigit(*right_it) != 0) {
+        right_num = std::stoull(right.substr(right_it - right.begin()), &right_pos);
+      }
+      left_it += static_cast<std::string::difference_type>(left_pos);
+      right_it += static_cast<std::string::difference_type>(right_pos);
+      if (right_pos == 0) {
+        if (left_pos != 0) {
+          return false;
+        }
+        if (left_depth < right_depth) {
+          return true;
+        }
+        if (right_depth > left_depth) {
+          return false;
+        }
+      }
+      else if (left_pos == 0) {
+        return true;
+      }
+      if (right_num < left_num) {
+        return false;
+      }
+      if (left_num < right_num) {
+        return true;
+      }
+
+      while (left_it != left.end() && *left_it == ']') {
+        --left_depth;
+        ++left_it;
+      }
+      while (right_it != right.end() && *right_it == ']') {
+        --right_depth;
+        ++right_it;
+      }
+      if (left_depth != right_depth) {
+        return left_depth < right_depth;
+      }
+      if (left_it != left.end() && *left_it == ',') {
+        ++left_it;
+      }
+      if (right_it != left.end() && *right_it == ',') {
+        ++right_it;
+      }
+    }
+
+    return left_it == left.end();
+  }
+};
+
+auto main() -> int
+{
+  std::string line;
+  std::set<std::string, Ordering> strings;
+  strings.insert("[[2]]");
+  strings.insert("[[6]]");
+
+  while (std::getline(std::cin, line)) {
+    if (line.empty()) {
+      continue;
+    }
+    strings.insert(line);
+  }
+  UInt dist2{0};
+  UInt dist6{0};
+  UInt idx{1};
+  for (auto const& s : strings) {
+    if (Ordering{}(s, "[[2]]")) {
+      ++dist2;
+      ++dist6;
+    }
+    else if (Ordering{}(s, "[[6]]")) {
+      ++dist6;
+    }
+    std::cout << idx++ << ": " << s << '\n';
+  }
+  std::cout << "Score: " << dist2 << " * " << dist6 << " = " << dist2 * dist6 << '\n';
+  return 0;
+}