From 3223948f511f76570c2820135bb47f29a831e9a2 Mon Sep 17 00:00:00 2001
From: Benjamin Kraft <benjamin.kraft@online.de>
Date: Tue, 19 Dec 2023 00:57:46 +0100
Subject: [PATCH] Day 5

---
 src/days/05/Day05.cpp | 122 ++++++++++++++++++++++++++++++++++++++++--
 src/days/05/Day05.h   |  22 ++++++++
 2 files changed, 141 insertions(+), 3 deletions(-)

diff --git a/src/days/05/Day05.cpp b/src/days/05/Day05.cpp
index 34bffac..eaca7c7 100644
--- a/src/days/05/Day05.cpp
+++ b/src/days/05/Day05.cpp
@@ -1,9 +1,125 @@
 #include "Day05.h"
 
 Result Day05::Task1() {
-    return Day::Task1();
+	auto seeds = parseSeeds();
+	auto maps = parseMaps();
+
+	uint64 min = UINT64_MAX;
+
+	for (uint64 seed : seeds){
+		uint64 result = seed;
+		for (const Map &map : maps)
+			result = map.get(result);
+		min = std::min(min, result);
+	}
+
+    return to_string(min);
 }
 
 Result Day05::Task2() {
-    return Day::Task2();
-}
\ No newline at end of file
+	auto seeds = parseSeeds();
+	auto maps = parseMaps();
+
+	uint64 min = UINT64_MAX;
+
+	for (size_t i = 0; i < seeds.size(); i += 2){
+		vector<Range> resultRanges {Range(seeds[i], seeds[i] + seeds[i + 1] - 1)};
+		for (const Map &map : maps){
+			vector<Range> newRanges;
+			for (const Range &range : resultRanges) {
+				auto add = map.get(range);
+				std::copy(add.begin(), add.end(), std::back_inserter(newRanges));
+			}
+			resultRanges = newRanges;
+		}
+		for (const Range &range : resultRanges)
+			min = std::min(min, range.start);
+	}
+
+	return to_string(min);
+}
+
+vector<uint64> Day05::parseSeeds() const {
+	vector<uint64> seeds;
+	auto list = (input[0] + " ").substr(7);
+	size_t start = 0;
+	for (size_t i : findAll(list, " ")){
+		seeds.push_back(std::stoul(list.substr(start, i - start)));
+		start = i;
+	}
+
+	return seeds;
+}
+
+std::array<Day05::Map, 7> Day05::parseMaps() const {
+	std::array<Map, 7> maps;
+
+	size_t map = 0;
+
+	for (size_t i = 3; i < input.size(); i++){
+		string line = input[i];
+		if (line.empty()){
+			i++;
+			map++;
+			continue;
+		}
+
+		vector<string> values = split(line, ' ');
+		maps[map].mappings.insert(Mapping(std::stoul(values[0]), std::stoul(values[1]), std::stoul(values[2])));
+	}
+
+	return maps;
+}
+
+uint64 Day05::Mapping::get(uint64 src) const {
+	return src - source + destination;
+}
+
+Day05::Range Day05::Mapping::get(Day05::Range src) const {
+	if (containsKey(src.start) && containsKey(src.end))
+		return Range(get(src.start), get(src.end));
+	if (containsKey(src.start))
+		return Range(get(src.start), get(source + range - 1));
+	if (containsKey(src.end))
+		return Range(get(source), get(src.end));
+	return Range(get(source), get(source + range - 1));
+}
+
+bool Day05::Mapping::touchesRange(Day05::Range src) const {
+	return !(src.end < source || src.start > source + range - 1);
+}
+
+
+uint64 Day05::Map::get(uint64 src) const {
+	for (const Mapping &mapping : mappings)
+		if (mapping.containsKey(src))
+			return mapping.get(src);
+	return src;
+}
+
+vector<Day05::Range> Day05::Map::get(Day05::Range src) const {
+	vector<Range> ranges;
+
+	uint64 minSource = mappings.begin()->source;
+	uint64 maxSource = (--mappings.end())->source + (--mappings.end())->range - 1;
+	if (src.end < minSource || src.start > maxSource)
+		return {src};
+	if (src.start < minSource)
+		ranges.emplace_back(src.start, minSource - 1);
+	if (src.end > maxSource)
+		ranges.emplace_back(maxSource + 1, src.end);
+
+	for (const Mapping &mapping : mappings)
+		if (mapping.touchesRange(src))
+			ranges.emplace_back(mapping.get(src));
+
+	return ranges;
+}
+
+bool Day05::Mapping::containsKey(uint64 src) const {
+	return src >= source && src < source + range;
+}
+
+bool Day05::Mapping::operator<(const Day05::Mapping &other) const {
+	return source < other.source;
+}
diff --git a/src/days/05/Day05.h b/src/days/05/Day05.h
index 128dacd..34b7036 100644
--- a/src/days/05/Day05.h
+++ b/src/days/05/Day05.h
@@ -3,8 +3,30 @@
 #include "../../Day.h"
 
 class Day05 : public Day {
+	struct Range {
+		uint64 start;
+		uint64 end;
+	};
+	struct Mapping {
+		uint64 destination;
+		uint64 source;
+		uint64 range;
+		bool containsKey(uint64 src) const;
+		uint64 get(uint64 src) const;
+		bool touchesRange(Range src) const;
+		Range get(Range src) const;
+		bool operator <(const Mapping &other) const;
+	};
+	struct Map {
+		set<Mapping> mappings;
+		uint64 get(uint64 src) const;
+		vector<Range> get(Range src) const;
+	};
 protected:
     Result Task1() override;
 
     Result Task2() override;
+
+	vector<uint64> parseSeeds() const;
+	std::array<Map, 7> parseMaps() const;
 };
\ No newline at end of file