From d57308ea8334480f30c1f3aea3fc7ebc82b55a2d Mon Sep 17 00:00:00 2001
From: Matthew Gretton-Dann <matt@gretton-dann.org.uk>
Date: Tue, 6 Dec 2022 10:51:17 +0000
Subject: [PATCH] Add 2022 Day 6.

---
 2022/puzzle-06-01.cc | 30 ++++++++++++++++++++++++++++++
 2022/puzzle-06-02.cc | 30 ++++++++++++++++++++++++++++++
 2 files changed, 60 insertions(+)
 create mode 100644 2022/puzzle-06-01.cc
 create mode 100644 2022/puzzle-06-02.cc

diff --git a/2022/puzzle-06-01.cc b/2022/puzzle-06-01.cc
new file mode 100644
index 0000000..a8419b7
--- /dev/null
+++ b/2022/puzzle-06-01.cc
@@ -0,0 +1,30 @@
+//
+// Created by Matthew Gretton-Dann on 05/12/2021.
+//
+
+#include <bitset>
+#include <iostream>
+#include <string>
+#include <vector>
+
+using UInt = std::uint64_t;
+
+auto main() -> int
+{
+  std::string line;
+  unsigned const match_len{4};
+  while (std::getline(std::cin, line) && !line.empty()) {
+    std::bitset<UCHAR_MAX> bits;
+    for (UInt i{0}; i != line.size(); ++i) {
+      bits.flip(static_cast<unsigned char>(line[i]));
+      if (i >= match_len) {
+        bits.flip(static_cast<unsigned char>(line[i - match_len]));
+      }
+      if (i >= (match_len - 1) && bits.count() == match_len) {
+        std::cout << "First match at " << i + 1 << '\n';
+        break;
+      }
+    }
+  }
+  return 0;
+}
diff --git a/2022/puzzle-06-02.cc b/2022/puzzle-06-02.cc
new file mode 100644
index 0000000..cd7ac01
--- /dev/null
+++ b/2022/puzzle-06-02.cc
@@ -0,0 +1,30 @@
+//
+// Created by Matthew Gretton-Dann on 05/12/2021.
+//
+
+#include <bitset>
+#include <iostream>
+#include <string>
+#include <vector>
+
+using UInt = std::uint64_t;
+
+auto main() -> int
+{
+  std::string line;
+  unsigned const match_len{14};
+  while (std::getline(std::cin, line) && !line.empty()) {
+    std::bitset<UCHAR_MAX> bits;
+    for (UInt i{0}; i != line.size(); ++i) {
+      bits.flip(static_cast<unsigned char>(line[i]));
+      if (i >= match_len) {
+        bits.flip(static_cast<unsigned char>(line[i - match_len]));
+      }
+      if (i >= (match_len - 1) && bits.count() == match_len) {
+        std::cout << "First match at " << i + 1 << '\n';
+        break;
+      }
+    }
+  }
+  return 0;
+}