userspace/aoc2024/CMakeLists.txt

@@ -11,7 +11,6 @@ set(AOC2024_PROJECTS
 	day10
 	day11
 	day12
-	day13
 	full
 )
 

userspace/aoc2024/day12/main.cpp

@@ -1,6 +1,7 @@
-#include <BAN/Queue.h>
+#include <BAN/HashMap.h>
-#include <BAN/Sort.h>
+#include <BAN/HashSet.h>
 #include <BAN/Vector.h>
+#include <BAN/Queue.h>
 
 #include <inttypes.h>
 #include <stdio.h>
@@ -27,6 +28,33 @@ struct Position
 	}
 };
 
+struct PositionHash
+{
+	constexpr BAN::hash_t operator()(Position state) const
+	{
+		return BAN::hash<u64>{}((u64)state.x << 32 | (u64)state.y);
+	}
+};
+
+struct PosDir
+{
+	Position pos;
+	u8 dir;
+
+	constexpr bool operator==(PosDir other) const
+	{
+		return pos == other.pos && dir == other.dir;
+	}
+};
+
+struct PosDirHash
+{
+	constexpr BAN::hash_t operator()(PosDir state) const
+	{
+		return PositionHash{}(state.pos) ^ BAN::hash<uint8_t>{}(state.dir);
+	}
+};
+
 struct Grid2D
 {
 	usize width { 0 };
@@ -78,8 +106,7 @@ i64 part1(FILE* fp)
 {
 	auto map = read_grid2d(fp);
 
-	BAN::Vector<bool> checked;
+	BAN::HashSet<Position, PositionHash> checked;
-	MUST(checked.resize(map.width * map.height, false));
 
 	i64 result = 0;
 
@@ -88,7 +115,7 @@ i64 part1(FILE* fp)
 		for (u32 x = 0; x < map.width; x++)
 		{
 			const auto pos = Position { .x = x, .y = y };
-			if (checked[map.width * pos.y + pos.x])
+			if (checked.contains(pos))
 				continue;
 
 			const char target = map.get(pos.x, pos.y);
@@ -110,9 +137,9 @@ i64 part1(FILE* fp)
 					continue;
 				}
 
-				if (checked[map.width * pos.y + pos.x])
+				if (checked.contains(pos))
 					continue;
-				checked[map.width * pos.y + pos.x] = true;
+				MUST(checked.insert(pos));
 
 				area++;
 
@@ -133,8 +160,7 @@ i64 part2(FILE* fp)
 {
 	auto map = read_grid2d(fp);
 
-	BAN::Vector<bool> checked;
+	BAN::HashSet<Position, PositionHash> checked;
-	MUST(checked.resize(map.width * map.height, false));
 
 	i64 result = 0;
 
@@ -143,82 +169,67 @@ i64 part2(FILE* fp)
 		for (u32 x = 0; x < map.width; x++)
 		{
 			const auto pos = Position { .x = x, .y = y };
-			if (checked[map.width * pos.y + pos.x])
+			if (checked.contains(pos))
 				continue;
 
 			const char target = map.get(pos.x, pos.y);
 
-			struct PerimeterEntry
-			{
-				Position pos;
-				bool counted;
-			};
-			BAN::Vector<PerimeterEntry> perimiters[4];
-
-			struct CheckEntry
-			{
-				Position pos;
-				uint8_t dir;
-			};
-			BAN::Queue<CheckEntry> checking;
-			MUST(checking.push({ .pos = pos, .dir = 0 }));
-
 			u32 area = 0;
+			BAN::HashMap<PosDir, bool, PosDirHash> perimiter;
+
+			BAN::Queue<PosDir> checking;
+			MUST(checking.push({ .pos = pos, .dir = 0 }));
 
 			while (!checking.empty())
 			{
-				const auto [pos, dir] = checking.front();
+				auto pos_dir = checking.front();
 				checking.pop();
 
-				if (pos.x >= map.width || pos.y >= map.height || map.get(pos.x, pos.y) != target)
+				if (pos_dir.pos.x >= map.width || pos_dir.pos.y >= map.height || map.get(pos_dir.pos.x, pos_dir.pos.y) != target)
 				{
-					MUST(perimiters[dir].emplace_back(pos, true));
+					MUST(perimiter.insert(pos_dir, true));
 					continue;
 				}
 
-				if (checked[map.width * pos.y + pos.x])
+				if (checked.contains(pos_dir.pos))
 					continue;
-				checked[map.width * pos.y + pos.x] = true;
+				MUST(checked.insert(pos_dir.pos));
 
 				area++;
 
+				const auto pos = pos_dir.pos;
 				MUST(checking.push({ .pos { .x = pos.x + 1, .y = pos.y + 0 }, .dir = 0 }));
 				MUST(checking.push({ .pos { .x = pos.x - 1, .y = pos.y + 0 }, .dir = 1 }));
 				MUST(checking.push({ .pos { .x = pos.x + 0, .y = pos.y + 1 }, .dir = 2 }));
 				MUST(checking.push({ .pos { .x = pos.x + 0, .y = pos.y - 1 }, .dir = 3 }));
 			}
 
-			for (auto& perimiter : perimiters)
+			for (auto it1 = perimiter.begin(); it1 != perimiter.end(); it1++)
 			{
-				BAN::sort::sort(perimiter.begin(), perimiter.end(),
+				for (auto it2 = BAN::next(it1, 1); it2 != perimiter.end(); it2++)
-					[](const auto& a, const auto& b) -> bool
-					{
-						if (a.pos.x != b.pos.x)
-							return a.pos.x < b.pos.x;
-						return a.pos.y < b.pos.y;
-					}
-				);
-
-				for (auto it1 = perimiter.begin(); it1 != perimiter.end(); it1++)
 				{
-					for (auto it2 = it1 + 1; it2 != perimiter.end(); it2++)
+					if (it1->key.dir != it2->key.dir)
-					{
+						continue;
-						if (it1->pos.x != it2->pos.x && it1->pos.y != it2->pos.y)
+					if (it1->key.pos.x != it2->key.pos.x && it1->key.pos.y != it2->key.pos.y)
-							continue;
+						continue;
-						if (!it2->counted)
+
-							continue;
+					auto min_it = it1, max_it = it2;
-						const u32 diff_x = it2->pos.x - it1->pos.x;
+					if (min_it->key.pos.x > max_it->key.pos.x || min_it->key.pos.y > max_it->key.pos.y)
-						const u32 diff_y = it2->pos.y - it1->pos.y;
+						BAN::swap(min_it, max_it);
-						if ((diff_x == 0 && diff_y == 1) || (diff_x == 1 && diff_y == 0))
+
-							it2->counted = false;
+					if (!max_it->value)
-					}
+						continue;
+
+					const u32 diff_x = max_it->key.pos.x - min_it->key.pos.x;
+					const u32 diff_y = max_it->key.pos.y - min_it->key.pos.y;
+					if ((diff_x == 0 && diff_y == 1) || (diff_x == 1 && diff_y == 0))
+						max_it->value = false;
 				}
 			}
 
 			u32 sides = 0;
-			for (const auto& perimiter : perimiters)
+			for (auto [_, count] : perimiter)
-				for (auto [_, counted] : perimiter)
+				sides += count;
-					sides += counted;
 
 			result += area * sides;
 		}

userspace/aoc2024/day13/CMakeLists.txt

@@ -1,9 +0,0 @@
-set(SOURCES
-	main.cpp
-)
-
-add_executable(aoc2024_day13 ${SOURCES})
-banan_include_headers(aoc2024_day13 ban)
-banan_link_library(aoc2024_day13 libc)
-
-install(TARGETS aoc2024_day13 OPTIONAL)

userspace/aoc2024/day13/main.cpp

@@ -1,115 +0,0 @@
-#include <BAN/Assert.h>
-#include <BAN/Math.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;
-using usize = size_t;
-
-struct vec_t { i64 x, y; };
-
-u64 fewest_tokens(vec_t a, vec_t b, vec_t p)
-{
-	ASSERT(a.x * b.y != b.x * a.y);
-
-	// n * a.x + m * b.x = p.x  <==>  m = (p.x - n * a.x) / b.x
-	// n * a.y + m * b.y = p.y
-
-	// n * a.y + ((p.x - n * a.x) / b.x) * b.y = p.y
-	// => n * a.y + (p.x / b.x - n * a.x / b.x) * b.y = p.y
-	// => n * a.y + p.x / b.x * b.y - n * a.x / b.x * b.y = p.y
-	// => n * a.y - n * a.x / b.x * b.y = p.y - p.x / b.x * b.y
-	// => n * a.y * b.x - n * a.x * b.y = p.y * b.x - p.x * b.y
-	// => n * (a.y * b.x - a.x * b.y) = p.y * b.x - p.x * b.y
-	// => n = (p.y * b.x - p.x * b.y) / (a.y * b.x - a.x * b.y)
-
-	const i64 n_num = p.y * b.x - p.x * b.y;
-	const i64 n_den = a.y * b.x - a.x * b.y;
-	if (n_num % n_den)
-		return 0;
-	const i64 n = n_num / n_den;
-
-	const i64 m_num = p.x - n * a.x;
-	const i64 m_den = b.x;
-	if (m_num % m_den)
-		return 0;
-	const i64 m = m_num / m_den;
-
-	return 3 * n + m;
-}
-
-i64 part1(FILE* fp)
-{
-	i64 result = 0;
-
-	for (;;)
-	{
-		constexpr const char* format =
-			"Button A: X+%" SCNd64 ", Y+%" SCNd64 "\n"
-			"Button B: X+%" SCNd64 ", Y+%" SCNd64 "\n"
-			"Prize: X=%" SCNd64 ", Y=%" SCNd64 "\n";
-
-		vec_t a, b, prize;
-		if (fscanf(fp, format, &a.x, &a.y, &b.x, &b.y, &prize.x, &prize.y) != 6)
-			break;
-
-		result += fewest_tokens(a, b, prize);
-	}
-
-	return result;
-}
-
-i64 part2(FILE* fp)
-{
-	i64 result = 0;
-
-	for (;;)
-	{
-		constexpr const char* format =
-			"Button A: X+%" SCNu64 ", Y+%" SCNu64 "\n"
-			"Button B: X+%" SCNu64 ", Y+%" SCNu64 "\n"
-			"Prize: X=%" SCNu64 ", Y=%" SCNu64 "\n";
-
-		vec_t a, b, prize;
-		if (fscanf(fp, format, &a.x, &a.y, &b.x, &b.y, &prize.x, &prize.y) != 6)
-			break;
-
-		prize.x += 10000000000000;
-		prize.y += 10000000000000;
-		result += fewest_tokens(a, b, prize);
-	}
-
-	return result;
-}
-
-int main(int argc, char** argv)
-{
-	const char* file_path = "/usr/share/aoc2024/day13_input.txt";
-
-	if (argc >= 2)
-		file_path = argv[1];
-
-	FILE* fp = fopen(file_path, "r");
-	if (fp == nullptr)
-	{
-		perror("fopen");
-		return 1;
-	}
-
-	printf("part1: %" PRId64 "\n", part1(fp));
-
-	fseek(fp, 0, SEEK_SET);
-
-	printf("part2: %" PRId64 "\n", part2(fp));
-
-	fclose(fp);
-}