From 3117a35581a6cd521e132a2791da9b804cc9c90f Mon Sep 17 00:00:00 2001
From: Matthew Gretton-Dann <matt@gretton-dann.org.uk>
Date: Sun, 4 Dec 2022 08:12:44 +0000
Subject: [PATCH] Add 2022 Day 4.

---
 2022/puzzle-04-01.cc | 44 ++++++++++++++++++++++++++++++++++++
 2022/puzzle-04-02.cc | 53 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 97 insertions(+)
 create mode 100644 2022/puzzle-04-01.cc
 create mode 100644 2022/puzzle-04-02.cc

diff --git a/2022/puzzle-04-01.cc b/2022/puzzle-04-01.cc
new file mode 100644
index 0000000..4cddf9f
--- /dev/null
+++ b/2022/puzzle-04-01.cc
@@ -0,0 +1,44 @@
+//
+// Created by Matthew Gretton-Dann on 05/12/2021.
+//
+
+#include <iostream>
+#include <map>
+#include <numeric>
+#include <regex>
+#include <string>
+
+using UInt = std::uint64_t;
+using Point = std::pair<UInt, UInt>;
+
+auto contained_in(Point const& super, Point const& sub) noexcept -> bool
+{
+  return super.first <= sub.first && super.second >= sub.second;
+}
+
+auto get_points(std::string const& s) -> std::pair<Point, Point>
+{
+  static std::regex re{R"((\d+)-(\d+),(\d+)-(\d+))"};
+  std::smatch m;
+  if (!std::regex_search(s, m, re)) {
+    std::cerr << "Unable to interpret: " << s << "\n";
+    std::exit(1);
+  }
+  return {{std::stoul(m.str(1)), std::stoul(m.str(2))},
+          {std::stoul(m.str(3)), std::stoul(m.str(4))}};
+}
+
+auto main() -> int
+{
+  std::string line;
+  UInt count{0};
+  while (std::getline(std::cin, line)) {
+    auto [pt1, pt2] = get_points(line);
+    if (contained_in(pt1, pt2) || contained_in(pt2, pt1)) {
+      ++count;
+    }
+  }
+
+  std::cout << "Completely duplicated effort: " << count << '\n';
+  return 0;
+}
diff --git a/2022/puzzle-04-02.cc b/2022/puzzle-04-02.cc
new file mode 100644
index 0000000..44c6506
--- /dev/null
+++ b/2022/puzzle-04-02.cc
@@ -0,0 +1,53 @@
+//
+// Created by Matthew Gretton-Dann on 05/12/2021.
+//
+
+#include <iostream>
+#include <map>
+#include <numeric>
+#include <regex>
+#include <string>
+
+using UInt = std::uint64_t;
+using Point = std::pair<UInt, UInt>;
+
+auto contained_in(Point const& super, Point const& sub) noexcept -> bool
+{
+  return super.first <= sub.first && super.second >= sub.second;
+}
+
+auto overlap(Point const& l, Point const& r) noexcept -> bool
+{
+  //  aaaa --- bbbb
+  //  aaCCbb
+  //  bbCCaa
+  //  bbbb --  aaaa
+  return l.second >= r.first && l.first <= r.second;
+}
+
+auto get_points(std::string const& s) -> std::pair<Point, Point>
+{
+  static std::regex re{R"((\d+)-(\d+),(\d+)-(\d+))"};
+  std::smatch m;
+  if (!std::regex_search(s, m, re)) {
+    std::cerr << "Unable to interpret: " << s << "\n";
+    std::exit(1);
+  }
+  return {{std::stoul(m.str(1)), std::stoul(m.str(2))},
+          {std::stoul(m.str(3)), std::stoul(m.str(4))}};
+}
+
+auto main() -> int
+{
+  std::string line;
+  UInt count{0};
+  while (std::getline(std::cin, line)) {
+    auto [pt1, pt2] = get_points(line);
+    if (overlap(pt2, pt1)) {
+      ++count;
+    }
+  }
+
+  std::cout << "Completely duplicated effort: " << count << '\n';
+  return 0;
+}