days/day01.cpp

@@ -72,7 +72,46 @@ To find the total distance between the left list and the right list, add up the
 you found. In the example above, this is 2 + 1 + 0 + 1 + 2 + 5, a total distance of 11!
 
 Your actual left and right lists contain many location IDs. What is the total distance between your lists?
+*/
 
+void day01::Part1()
+{
+	std::vector<int> col1;
+	std::vector<int> col2;
+	int sum = 0;
+
+	std::ifstream input("input/day01.txt");
+
+	if (!input)
+	{
+		std::cerr << "Failed to open input file." << std::endl;
+		std::cout << "Current path is " << std::filesystem::current_path() << '\n';
+
+		return;
+	}
+
+	std::string delimiter = "   ";
+	auto delimiterLength = delimiter.length();
+
+	std::string line;
+	while (std::getline(input, line))
+	{
+		auto delimiterPos = line.find(delimiter);
+		col1.emplace_back(std::stoi(line.substr(0, delimiterPos)));
+		col2.emplace_back(std::stoi(line.substr(delimiterPos + delimiterLength, line.length())));
+	}
+
+	std::sort(col1.begin(), col1.end());
+	std::sort(col2.begin(), col2.end());
+
+
+	for (int i = 0; i < col1.size(); ++i)
+	{
+		sum += std::abs(col1[i] - col2[i]);
+	}
+}
+
+/*
 --- Part Two ---
 
 Your analysis only confirmed what everyone feared: the two lists of location IDs are indeed very different.
@@ -111,20 +150,15 @@ Once again consider your left and right lists. What is their similarity score?
 
  */
 
-void day01::Calculate()
+void day01::Part2()
 {
 	std::vector<int> col1;
 	std::vector<int> col2;
 	std::unordered_map<int, int> occurrence_map;
-	int totalDistance = 0;
-	int similarityScore = 0;
-
-	size_t estimated_size = 1000;
-	col1.reserve(estimated_size);
-	col2.reserve(estimated_size);
-	occurrence_map.reserve(estimated_size);
+	int sum = 0;
 
 	std::ifstream input("input/day01.txt");
+	//std::ifstream input("input/day01short.txt");
 
 	if (!input)
 	{
@@ -134,28 +168,31 @@ void day01::Calculate()
 		return;
 	}
 
+	std::string delimiter = "   ";
+	auto delimiterLength = delimiter.length();
+
 	std::string line;
-	int num1, num2;
-	while (input >> num1 >> num2)
+	while (std::getline(input, line))
 	{
-		col1.emplace_back(num1);
-		col2.emplace_back(num2);
-		occurrence_map[num2]++;
+		auto delimiterPos = line.find(delimiter);
+		col1.emplace_back(std::stoi(line.substr(0, delimiterPos)));
+		col2.emplace_back(std::stoi(line.substr(delimiterPos + delimiterLength, line.length())));
 	}
 
-	std::sort(col1.begin(), col1.end());
-	std::sort(col2.begin(), col2.end());
-
-	for (size_t i = 0; i < col1.size(); i++)
+	for (auto number: col2)
 	{
-		totalDistance += std::abs(col1[i] - col2[i]);
-		similarityScore += col1[i] * occurrence_map[col1[i]];
+		if (occurrence_map.contains(number))
+		{
+			occurrence_map[number]++;
+		} else
+		{
+			occurrence_map[number] = 1;
+		}
 	}
 
-	printf("Total distance: %d\n", totalDistance);
-	printf("Similarity score: %d\n", similarityScore);
+	for (auto number: col1)
+	{
+		sum += number * occurrence_map[number];
+	}
+	printf("Sum of all occurrence pairs is: %d\n", sum);
 }
-
-//Correct answers:
-//part1: 1889772
-//part2: 23228917

days/day01.h

@@ -10,7 +10,7 @@ class day01
 {
 public:
 	static void Part1();
-	static void Calculate();
+	static void Part2();
 };
 
 

main.cpp

@@ -5,26 +5,9 @@
 
 int main()
 {
-	double lowest = 10000;
-	double totalTime = 0;
-	constexpr int cycles = 1;
-	//constexpr int cycles = 10000;
-	for (int i = 1; i <= cycles; i++)
-	{
-		const auto startTime = std::chrono::high_resolution_clock::now();
-		day01::Calculate();
-		const auto endTime = std::chrono::high_resolution_clock::now();
-		const std::chrono::duration<double> diff = endTime - startTime;
-
-		totalTime += diff.count();
-		if (diff.count() < lowest)
-		{
-			lowest = diff.count();
-		}
-	}
-	const double average = totalTime / cycles;
-	std::cout << "Ran " << cycles << " cycles. "
-			<< "Execution time avg: " << average * 1e6 << " μs. Lowest: "
-			<< lowest
-			* 1e6 << " μs" << std::endl;
+	const auto startTime = std::chrono::high_resolution_clock::now();
+	day01::Part2();
+	const auto endTime = std::chrono::high_resolution_clock::now();
+	const std::chrono::duration<double> diff = endTime - startTime;
+	std::cout << "Execution time: " << diff.count() * 1e6 << " μs" << std::endl;
 }