combined part 1 and 2

I don't want to hardcode the number of lines in the input file.

days/day01.cpp

@@ -72,46 +72,7 @@ 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.
@@ -150,15 +111,20 @@ Once again consider your left and right lists. What is their similarity score?
 
  */
 
-void day01::Part2()
+void day01::Calculate()
 {
 	std::vector<int> col1;
 	std::vector<int> col2;
 	std::unordered_map<int, int> occurrence_map;
-	int sum = 0;
+	int totalDistance = 0;
+	int similarityScore = 0;
+
+	size_t estimated_size = 1000;
+	col1.reserve(estimated_size);
+	col2.reserve(estimated_size);
+	occurrence_map.reserve(estimated_size);
 
 	std::ifstream input("input/day01.txt");
-	//std::ifstream input("input/day01short.txt");
 
 	if (!input)
 	{
@@ -168,31 +134,28 @@ void day01::Part2()
 		return;
 	}
 
-	std::string delimiter = "   ";
-	auto delimiterLength = delimiter.length();
-
 	std::string line;
-	while (std::getline(input, line))
+	int num1, num2;
+	while (input >> num1 >> 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())));
+		col1.emplace_back(num1);
+		col2.emplace_back(num2);
+		occurrence_map[num2]++;
 	}
 
-	for (auto number: col2)
+	std::sort(col1.begin(), col1.end());
+	std::sort(col2.begin(), col2.end());
+
+	for (size_t i = 0; i < col1.size(); i++)
 	{
-		if (occurrence_map.contains(number))
-		{
-			occurrence_map[number]++;
-		} else
-		{
-			occurrence_map[number] = 1;
-		}
+		totalDistance += std::abs(col1[i] - col2[i]);
+		similarityScore += col1[i] * occurrence_map[col1[i]];
 	}
 
-	for (auto number: col1)
-	{
-		sum += number * occurrence_map[number];
-	}
-	printf("Sum of all occurrence pairs is: %d\n", sum);
+	printf("Total distance: %d\n", totalDistance);
+	printf("Similarity score: %d\n", similarityScore);
 }
+
+//Correct answers:
+//part1: 1889772
+//part2: 23228917

days/day01.h

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

main.cpp

@@ -5,9 +5,26 @@
 
 int main()
 {
-	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;
+	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;
 }