From ffa57208d5ae7fb46d8f46dfe9f8e975599f475f Mon Sep 17 00:00:00 2001
From: Eric Mertens <emertens@galois.com>
Date: Mon, 26 Aug 2024 11:04:02 -0700
Subject: [PATCH] Add 2015_08

---
 2015/08.cpp         | 70 +++++++++++++++++++++++++++++++++++++++++++++
 2015/CMakeLists.txt |  3 ++
 2 files changed, 73 insertions(+)
 create mode 100644 2015/08.cpp

diff --git a/2015/08.cpp b/2015/08.cpp
new file mode 100644
index 0000000..26e2492
--- /dev/null
+++ b/2015/08.cpp
@@ -0,0 +1,70 @@
+#include <aocpp/Startup.hpp>
+#include <doctest.h>
+
+#include <algorithm>
+#include <cstddef>
+#include <stdexcept>
+#include <string_view>
+
+auto rem_chars(std::string_view const str) -> std::size_t
+{
+  std::size_t result = 2; // two outer quotes
+  auto cursor = begin(str);
+  while (cursor != end(str))
+  {
+    if (*cursor++ == '\\')
+    {
+      if (cursor == end(str))
+        throw std::runtime_error{"bad input"};
+      auto const width = *cursor == 'x' ? 3 : 1;
+      result += width;
+      cursor += width;
+    }
+  }
+  return result;
+}
+
+auto needs_escape(char const c) -> bool
+{
+  return c == '\\' || c == '"';
+};
+
+auto add_chars(std::string_view const str) -> std::size_t
+{
+  return 2 + std::count_if(begin(str), end(str), needs_escape);
+}
+
+TEST_SUITE("documented examples") {
+using namespace std::string_view_literals;
+
+TEST_CASE("part 1") {
+  REQUIRE(2 == rem_chars(R"("")"sv));
+  REQUIRE(2 == rem_chars(R"("abc")"sv));
+  REQUIRE(3 == rem_chars(R"("aaa\"aaa")"sv));
+  REQUIRE(5 == rem_chars(R"("\x27")"sv));
+}
+
+TEST_CASE("part 2") {
+  REQUIRE(4 == add_chars(R"("")"));
+  REQUIRE(4 == add_chars(R"("abc")"sv));
+  REQUIRE(6 == add_chars(R"("aaa\"aaa")"sv));
+  REQUIRE(5 == add_chars(R"("\x27")"sv));
+}
+
+}
+
+auto Main(std::istream &in, std::ostream &out) -> void
+{
+  std::string line;
+  std::size_t part1 = 0;
+  std::size_t part2 = 0;
+
+  while (std::getline(in, line))
+  {
+    part1 += rem_chars(line);
+    part2 += add_chars(line);
+  }
+
+  out << "Part 1: " << part1 << std::endl;
+  out << "Part 2: " << part2 << std::endl;
+}
diff --git a/2015/CMakeLists.txt b/2015/CMakeLists.txt
index 7275f05..1238335 100644
--- a/2015/CMakeLists.txt
+++ b/2015/CMakeLists.txt
@@ -3,3 +3,6 @@ target_link_libraries(2015_01 aocpp)
 
 add_executable(2015_02 02.cpp)
 target_link_libraries(2015_02 aocpp)
+
+add_executable(2015_08 08.cpp)
+target_link_libraries(2015_08 aocpp)