From cea324cad9b86f4e8cb875f9bd7e35765cb7828d Mon Sep 17 00:00:00 2001
From: Matthew Gretton-Dann <matt@gretton-dann.org.uk>
Date: Wed, 15 Dec 2021 11:18:48 +0000
Subject: [PATCH] Add 2017 day 9 puzzles

---
 2017/puzzle-09-01.cc | 41 +++++++++++++++++++++++++++++++++++++++
 2017/puzzle-09-02.cc | 46 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 87 insertions(+)
 create mode 100644 2017/puzzle-09-01.cc
 create mode 100644 2017/puzzle-09-02.cc

diff --git a/2017/puzzle-09-01.cc b/2017/puzzle-09-01.cc
new file mode 100644
index 0000000..671cd2e
--- /dev/null
+++ b/2017/puzzle-09-01.cc
@@ -0,0 +1,41 @@
+#include <iostream>
+#include <string>
+
+auto main() -> int
+{
+  std::string line;
+  if (!std::getline(std::cin, line)) {
+    std::cerr << "Unable to parse line\n";
+    return 1;
+  }
+
+  unsigned score{0};
+  unsigned depth{0};
+  bool skip{false};
+  bool in_garbage{false};
+
+  for (auto c : line) {
+    if (skip) {
+      skip = false;
+    }
+    else if (in_garbage && c == '!') {
+      skip = true;
+    }
+    else if (in_garbage && c == '>') {
+      in_garbage = false;
+    }
+    else if (!in_garbage && c == '{') {
+      ++depth;
+      score += depth;
+    }
+    else if (!in_garbage && c == '}') {
+      --depth;
+    }
+    else if (!in_garbage && c == '<') {
+      in_garbage = true;
+    }
+  }
+
+  std::cout << "Score = " << score << '\n';
+  return 0;
+}
diff --git a/2017/puzzle-09-02.cc b/2017/puzzle-09-02.cc
new file mode 100644
index 0000000..6401453
--- /dev/null
+++ b/2017/puzzle-09-02.cc
@@ -0,0 +1,46 @@
+#include <iostream>
+#include <string>
+
+auto main() -> int
+{
+  std::string line;
+  if (!std::getline(std::cin, line)) {
+    std::cerr << "Unable to parse line\n";
+    return 1;
+  }
+
+  unsigned score{0};
+  unsigned garbage_count{0};
+  unsigned depth{0};
+  bool skip{false};
+  bool in_garbage{false};
+
+  for (auto c : line) {
+    if (skip) {
+      skip = false;
+    }
+    else if (in_garbage && c == '!') {
+      skip = true;
+    }
+    else if (in_garbage && c == '>') {
+      in_garbage = false;
+    }
+    else if (!in_garbage && c == '{') {
+      ++depth;
+      score += depth;
+    }
+    else if (!in_garbage && c == '}') {
+      --depth;
+    }
+    else if (!in_garbage && c == '<') {
+      in_garbage = true;
+    }
+    else if (in_garbage) {
+      ++garbage_count;
+    }
+  }
+
+  std::cout << "Score = " << score << '\n';
+  std::cout << "Garbage count = " << garbage_count << '\n';
+  return 0;
+}