AOC2023: Implement day19 part 1

userspace/aoc2023/CMakeLists.txt

@@ -21,6 +21,7 @@ set(AOC2023_PROJECTS
 	day16
 	day17
 	day18
+	day19
 	full
 )
 

userspace/aoc2023/day19/CMakeLists.txt

@@ -0,0 +1,22 @@
+cmake_minimum_required(VERSION 3.26)
+
+project(aoc2023_day19 CXX)
+
+set(SOURCES
+	main.cpp
+)
+
+add_executable(aoc2023_day19 ${SOURCES})
+target_compile_options(aoc2023_day19 PUBLIC -O2 -g)
+target_link_libraries(aoc2023_day19 PUBLIC libc ban)
+
+add_dependencies(aoc2023_day19 libc-install ban-install)
+
+add_custom_target(aoc2023_day19-install
+	COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_BINARY_DIR}/aoc2023_day19 ${BANAN_AOC2023_BIN}/day19
+	DEPENDS aoc2023_day19
+	DEPENDS aoc2023_always
+)
+
+add_dependencies(aoc2023 aoc2023_day19)
+add_dependencies(aoc2023-install aoc2023_day19-install)

userspace/aoc2023/day19/main.cpp

@@ -0,0 +1,220 @@
+#include <BAN/HashMap.h>
+#include <BAN/HashSet.h>
+#include <BAN/String.h>
+#include <BAN/Vector.h>
+
+#include <ctype.h>
+#include <inttypes.h>
+#include <stdio.h>
+
+using i8  = int8_t;
+using i16 = int16_t;
+using i32 = int32_t;
+using i64 = int64_t;
+
+using u8  = uint8_t;
+using u16 = uint16_t;
+using u32 = uint32_t;
+using u64 = uint64_t;
+
+enum Variable { x, m, a, s };
+enum class Comparison { Less, Greater, Always };
+
+struct Rule
+{
+	Variable	operand1;
+	i64			operand2;
+	Comparison	comparison;
+
+	BAN::String	target;
+};
+
+using Workflows = BAN::HashMapUnstable<BAN::String, BAN::Vector<Rule>>;
+
+struct Item
+{
+	i64 values[4];
+
+	bool operator==(const Item& other) const
+	{
+		return memcmp(values, other.values, sizeof(values)) == 0;
+	}
+};
+
+struct ItemHash
+{
+	BAN::hash_t operator()(const Item& item) const
+	{
+		return BAN::hash<u64>()(item.values[0]) ^
+			   BAN::hash<u64>()(item.values[1]) ^
+			   BAN::hash<u64>()(item.values[2]) ^
+			   BAN::hash<u64>()(item.values[3]);
+	};
+};
+
+i64 parse_i64(BAN::StringView str)
+{
+	i64 result = 0;
+	for (size_t i = 0; i < str.size() && isdigit(str[i]); i++)
+		result = (result * 10) + (str[i] - '0');
+	return result;
+}
+
+bool get_line(FILE* fp, BAN::String& out)
+{
+	out.clear();
+
+	bool success = false;
+
+	char buffer[128];
+	while (fgets(buffer, sizeof(buffer), fp))
+	{
+		success = true;
+
+		MUST(out.append(buffer));
+		if (out.back() == '\n')
+		{
+			out.pop_back();
+			break;
+		}
+	}
+
+	return success;
+}
+
+Workflows parse_workflows(FILE* fp)
+{
+	Workflows workflows;
+
+	BAN::String line;
+	while (get_line(fp, line) && !line.empty())
+	{
+		auto name = line.sv().substring(0, *line.sv().find('{'));
+		MUST(workflows.emplace(name));
+
+		auto rule_str = line.sv().substring(*line.sv().find('{') + 1);
+		rule_str = rule_str.substring(0, rule_str.size() - 1);
+
+		auto rules_str = MUST(rule_str.split(','));
+
+		for (size_t i = 0; i < rules_str.size() - 1; i++)
+		{
+			Rule rule;
+			rule.operand1	=	(rules_str[i][0] == 'x') ? Variable::x :
+								(rules_str[i][0] == 'm') ? Variable::m :
+								(rules_str[i][0] == 'a') ? Variable::a :
+														   Variable::s;
+			rule.operand2	= parse_i64(rules_str[i].substring(2));
+			rule.comparison	= (rules_str[i][1] == '<') ? Comparison::Less : Comparison::Greater;
+			rule.target		= rules_str[i].substring(*rules_str[i].find(':') + 1);
+
+			MUST(workflows[name].push_back(BAN::move(rule)));
+		}
+
+		MUST(workflows[name].emplace_back(Variable::x, 0, Comparison::Always, rules_str.back()));
+	}
+
+	return workflows;
+}
+
+BAN::Vector<Item> parse_items(FILE* fp)
+{
+	BAN::Vector<Item> items;
+
+	BAN::String line;
+	while (get_line(fp, line) && !line.empty())
+	{
+		auto values = MUST(line.sv().substring(1, line.size() - 2).split(','));
+		ASSERT(values.size() == 4);
+		ASSERT(values[0][0] == 'x');
+		ASSERT(values[1][0] == 'm');
+		ASSERT(values[2][0] == 'a');
+		ASSERT(values[3][0] == 's');
+
+		Item item;
+		item.values[0] = parse_i64(values[0].substring(2));
+		item.values[1] = parse_i64(values[1].substring(2));
+		item.values[2] = parse_i64(values[2].substring(2));
+		item.values[3] = parse_i64(values[3].substring(2));
+	
+		MUST(items.push_back(item));
+	}
+
+	return items;
+}
+
+bool satifies_rule(const Item& item, const Rule& rule)
+{
+	switch (rule.comparison)
+	{
+		case Comparison::Always:
+			return true;
+		case Comparison::Less:
+			return item.values[rule.operand1] < rule.operand2;
+		case Comparison::Greater:
+			return item.values[rule.operand1] > rule.operand2;
+	}
+	ASSERT_NOT_REACHED();
+}
+
+bool is_accepted(const Item& item, const BAN::String& name, const Workflows& workflows)
+{
+	const auto& workflow = workflows[name];
+	for (const auto& rule : workflow)
+	{
+		if (!satifies_rule(item, rule))
+			continue;
+		if (rule.target == "A"sv)
+			return true;
+		if (rule.target == "R"sv)
+			return false;
+		return is_accepted(item, rule.target, workflows);
+	}
+	ASSERT_NOT_REACHED();
+}
+
+i64 puzzle1(FILE* fp)
+{
+	auto workflows = parse_workflows(fp);
+	auto items = parse_items(fp);
+
+	BAN::Vector<Item> accepted;
+
+	for (const auto& item : items)
+		if (is_accepted(item, "in"sv, workflows))
+			MUST(accepted.push_back(item));
+
+	i64 result = 0;
+	for (const auto& item : accepted)
+		result += item.values[0] + item.values[1] + item.values[2] + item.values[3];
+	return result;
+}
+
+i64 puzzle2(FILE* fp)
+{
+	(void)fp;
+	return -1;
+}
+
+int main(int argc, char** argv)
+{
+	const char* file_path = "/usr/share/aoc2023/day19_input.txt";
+
+	if (argc >= 2)
+		file_path = argv[1];
+
+	FILE* fp = fopen(file_path, "r");
+	if (fp == nullptr)
+	{
+		perror("fopen");
+		return 1;
+	}
+
+	printf("puzzle1: %" PRId64 "\n", puzzle1(fp));
+
+	fseek(fp, 0, SEEK_SET);
+
+	printf("puzzle2: %" PRId64 "\n", puzzle2(fp));
+
+	fclose(fp);
+}

userspace/aoc2023/full/main.cpp

@@ -4,7 +4,7 @@
 
 int main()
 {
-	for (int i = 1; i <= 18; i++)
+	for (int i = 1; i <= 19; i++)
 	{
 		printf("day %d:\n", i);