AOC2023: implement day5

userspace/aoc2023/CMakeLists.txt

@@ -7,6 +7,7 @@ set(AOC2023_PROJECTS
 	day2
 	day3
 	day4
+	day5
 )
 
 set(BANAN_AOC2023_BIN   ${BANAN_BIN}/aoc2023)

userspace/aoc2023/day5/CMakeLists.txt

@@ -0,0 +1,22 @@
+cmake_minimum_required(VERSION 3.26)
+
+project(aoc2023_day5 CXX)
+
+set(SOURCES
+	main.cpp
+)
+
+add_executable(aoc2023_day5 ${SOURCES})
+target_compile_options(aoc2023_day5 PUBLIC -O2 -g)
+target_link_libraries(aoc2023_day5 PUBLIC libc ban)
+
+add_dependencies(aoc2023_day5 libc-install ban-install)
+
+add_custom_target(aoc2023_day5-install
+	COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_BINARY_DIR}/aoc2023_day5 ${BANAN_AOC2023_BIN}/day5
+	DEPENDS aoc2023_day5
+	DEPENDS aoc2023_always
+)
+
+add_dependencies(aoc2023 aoc2023_day5)
+add_dependencies(aoc2023-install aoc2023_day5-install)

userspace/aoc2023/day5/main.cpp

@@ -0,0 +1,189 @@
+#include <BAN/HashMap.h>
+#include <BAN/Vector.h>
+
+#include <stdio.h>
+
+using i64 = int64_t;
+
+i64 parse_i64(BAN::StringView sv)
+{
+	i64 value = 0;
+	for (char c : sv)
+		value = (value * 10) + (c - '0');
+	return value;
+}
+
+i64 puzzle1(FILE* fp)
+{
+	struct Value
+	{
+		i64 value;
+		i64 depth;
+	};
+	BAN::Vector<Value> current;
+
+	char buffer[256];
+	if (!fgets(buffer, sizeof(buffer), fp))
+		return -1;
+	
+	{
+		BAN::StringView line(buffer);
+		line = line.substring(0, line.size() - 1);
+
+		auto seeds_str = MUST(line.split(' '));
+		for (i64 i = 1; i < seeds_str.size(); i++)
+			MUST(current.emplace_back(parse_i64(seeds_str[i]), 0));
+	}
+
+	fgets(buffer, sizeof(buffer), fp);
+	fgets(buffer, sizeof(buffer), fp);
+
+	i64 index = 1;
+
+	while (fgets(buffer, sizeof(buffer), fp))
+	{
+		if (*buffer == '\n')
+		{
+			index++;
+			fgets(buffer, sizeof(buffer), fp);
+			continue;
+		}
+
+		BAN::StringView line(buffer);
+		line = line.substring(0, line.size() - 1);
+
+		auto values_str = MUST(line.split(' '));
+
+		i64 dst = parse_i64(values_str[0]);
+		i64 src = parse_i64(values_str[1]);
+		i64 len = parse_i64(values_str[2]);
+
+		for (Value& value : current)
+		{
+			if (value.depth < index && src <= value.value && value.value < src + len)
+			{
+				value.value += dst - src;
+				value.depth = index;
+			}
+		}
+	}
+
+	i64 result = INT64_MAX;
+	for (const auto& value : current)
+		result = BAN::Math::min(value.value, result);
+	return result;
+}
+
+i64 puzzle2(FILE* fp)
+{
+	struct ValueRange
+	{
+		i64 value;
+		i64 length;
+		i64 depth;
+	};
+	BAN::Vector<ValueRange> current;
+
+	char buffer[256];
+	if (!fgets(buffer, sizeof(buffer), fp))
+		return -1;
+	
+	{
+		BAN::StringView line(buffer);
+		line = line.substring(0, line.size() - 1);
+		auto seeds_str = MUST(line.split(' '));
+		for (i64 i = 1; i < seeds_str.size(); i += 2)
+			MUST(current.emplace_back(parse_i64(seeds_str[i]), parse_i64(seeds_str[i + 1]), 0));
+	}
+
+	fgets(buffer, sizeof(buffer), fp);
+	fgets(buffer, sizeof(buffer), fp);
+
+	i64 index = 1;
+
+	while (fgets(buffer, sizeof(buffer), fp))
+	{
+		if (*buffer == '\n')
+		{
+			index++;
+			fgets(buffer, sizeof(buffer), fp);
+			continue;
+		}
+
+		BAN::StringView line(buffer);
+		line = line.substring(0, line.size() - 1);
+
+		auto values_str = MUST(line.split(' '));
+
+		i64 dst = parse_i64(values_str[0]);
+		i64 src = parse_i64(values_str[1]);
+		i64 len = parse_i64(values_str[2]);
+
+		for (size_t i = 0; i < current.size(); i++)
+		{
+			auto& range = current[i];
+			if (range.depth >= index)
+				continue;
+
+			// remap whole range (src range contains full range)
+			if (src <= range.value && range.value + range.length <= src + len)
+			{
+				range.value += dst - src;
+				range.depth = index;
+				continue;
+			}
+
+			// if current range contains any point from src range, split current range
+			i64 first_length = 0;
+			if (!first_length && range.value <= src && src < range.value + range.length)
+				first_length = src - range.value;
+			if (!first_length && range.value <= src + len - 1 && src + len - 1 < range.value + range.length)
+				first_length = (src + len) - range.value;
+			if (first_length)
+			{
+				ValueRange next_range;
+				next_range.value = range.value + first_length;
+				next_range.length = range.length - first_length;
+				next_range.depth = range.depth;
+
+				range.length = first_length;
+
+				MUST(current.insert(i + 1, next_range));
+
+				i--;
+				continue;
+			}
+
+			ASSERT(src + len - 1 < range.value || src > range.value + range.length - 1);
+		}
+	}
+
+	i64 result = INT64_MAX;
+	for (const auto& range : current)
+		if (range.length)
+			result = BAN::Math::min(range.value, result);
+	return result;
+}
+
+int main(int argc, char** argv)
+{
+	const char* file_path = "/usr/share/aoc2023/day5_input.txt";
+
+	if (argc >= 2)
+		file_path = argv[1];
+
+	FILE* fp = fopen(file_path, "r");
+	if (fp == nullptr)
+	{
+		perror("fopen");
+		return 1;
+	}
+
+	printf("puzzle1: %lld\n", puzzle1(fp));
+
+	fseek(fp, 0, SEEK_SET);
+
+	printf("puzzle2: %lld\n", puzzle2(fp));
+
+	fclose(fp);
+}