aoc 2015, days 12, 13 and 14

1 files changed, 78 insertions, 0 deletions

diff --git a/2015/src/day12.cpp b/2015/src/day12.cpp
new file mode 100644
index 0000000..2bb2e78
--- /dev/null
+++ b/2015/src/day12.cpp
@@ -0,0 +1,78 @@
+#include <fstream>
+#include <iostream>
+#include <iterator>
+#include <string>
+
+// JSON parsing
+#include <nlohmann/json.hpp>
+
+using namespace std;
+using json = nlohmann::json;
+
+string
+read_file(string_view filename)
+{
+        fstream input{ filename };
+        return { istreambuf_iterator{ input }, {} };
+}
+
+template<class UnaryFunction>
+void
+recursive_iterate(const json& j, UnaryFunction f) // NOLINT
+{
+        for ( auto it = j.begin(); it != j.end(); ++it ) {
+                if ( it->is_structured() ) {
+                        recursive_iterate(*it, f);
+                }
+                else {
+                        f(it);
+                }
+        }
+}
+
+void
+part1(string_view document)
+{
+        auto json = json::parse(document);
+
+        long sum = 0;
+        recursive_iterate(json, [&](json::const_iterator iter) {
+                if ( iter.value().is_number() ) {
+                        sum += iter.value().get<long>();
+                }
+        });
+        cout << sum << endl;
+}
+
+void
+part2(string_view document)
+{
+        json::parser_callback_t parser_callback = [](int /*depth*/, json::parse_event_t event, json& parsed) {
+                if ( event == json::parse_event_t::object_end ) {
+                        for ( auto it = parsed.begin(); it != parsed.end(); ++it ) {
+                                if ( it.value().is_string() && it.value().get<string>() == "red" ) {
+                                        return false;
+                                }
+                        }
+                }
+                return true;
+        };
+
+        auto json = json::parse(document, parser_callback);
+
+        long sum = 0;
+        recursive_iterate(json, [&](json::const_iterator iter) {
+                if ( iter.value().is_number() ) {
+                        sum += iter.value().get<long>();
+                }
+        });
+        cout << sum << endl;
+}
+
+int
+main()
+{
+        auto document = read_file("data/day12.txt");
+        part1(document);
+        part2(document);
+}