tos

.gitignore

@@ -1 +1,2 @@
-/cmake-build-debug/
+/cmake-build-debug/
+/challenge-text/

days/day01.cpp

@@ -12,104 +12,6 @@
 #include <bits/fs_fwd.h>
 #include <bits/fs_path.h>
 
-/*
---- Day 1: Historian Hysteria ---
-
-The Chief Historian is always present for the big Christmas sleigh launch, but nobody has seen him in months! Last
-anyone heard, he was visiting locations that are historically significant to the North Pole; a group of Senior
-Historians has asked you to accompany them as they check the places they think he was most likely to visit.
-
-As each location is checked, they will mark it on their list with a star. They figure the Chief Historian must be in
-one of the first fifty places they'll look, so in order to save Christmas, you need to help them get fifty stars on
-their list before Santa takes off on December 25th.
-
-Collect stars by solving puzzles. Two puzzles will be made available on each day in the Advent calendar; the second
-puzzle is unlocked when you complete the first. Each puzzle grants one star. Good luck!
-
-You haven't even left yet and the group of Elvish Senior Historians has already hit a problem: their list of locations
-to check is currently empty. Eventually, someone decides that the best place to check first would be the Chief
-Historian's office.
-
-Upon pouring into the office, everyone confirms that the Chief Historian is indeed nowhere to be found. Instead,
-the Elves discover an assortment of notes and lists of historically significant locations! This seems to be the
-planning the Chief Historian was doing before he left. Perhaps these notes can be used to determine which locations
-to search?
-
-Throughout the Chief's office, the historically significant locations are listed not by name but by a unique number
-called the location ID. To make sure they don't miss anything, The Historians split into two groups, each searching
-the office and trying to create their own complete list of location IDs.
-
-There's just one problem: by holding the two lists up side by side (your puzzle input), it quickly becomes clear
-that the lists aren't very similar. Maybe you can help The Historians reconcile their lists?
-
-For example:
-
-3   4
-4   3
-2   5
-1   3
-3   9
-3   3
-
-Maybe the lists are only off by a small amount! To find out, pair up the numbers and measure how far apart they are.
-Pair up the smallest number in the left list with the smallest number in the right list, then the second-smallest left
-number with the second-smallest right number, and so on.
-
-Within each pair, figure out how far apart the two numbers are; you'll need to add up all of those distances.
-For example, if you pair up a 3 from the left list with a 7 from the right list, the distance apart is 4; if you pair
-up a 9 with a 3, the distance apart is 6.
-
-In the example list above, the pairs and distances would be as follows:
-
-    The smallest number in the left list is 1, and the smallest number in the right list is 3. The distance between them is 2.
-    The second-smallest number in the left list is 2, and the second-smallest number in the right list is another 3. The distance between them is 1.
-    The third-smallest number in both lists is 3, so the distance between them is 0.
-    The next numbers to pair up are 3 and 4, a distance of 1.
-    The fifth-smallest numbers in each list are 3 and 5, a distance of 2.
-    Finally, the largest number in the left list is 4, while the largest number in the right list is 9; these are a distance 5 apart.
-
-To find the total distance between the left list and the right list, add up the distances between all the pairs
-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?
-
---- Part Two ---
-
-Your analysis only confirmed what everyone feared: the two lists of location IDs are indeed very different.
-
-Or are they?
-
-The Historians can't agree on which group made the mistakes or how to read most of the Chief's handwriting,
-but in the commotion you notice an interesting detail: a lot of location IDs appear in both lists! Maybe the other
-numbers aren't location IDs at all but rather misinterpreted handwriting.
-
-This time, you'll need to figure out exactly how often each number from the left list appears in the right
-list. Calculate a total similarity score by adding up each number in the left list after multiplying it by the number
-of times that number appears in the right list.
-
-Here are the same example lists again:
-
-3   4
-4   3
-2   5
-1   3
-3   9
-3   3
-
-For these example lists, here is the process of finding the similarity score:
-
-	The first number in the left list is 3. It appears in the right list three times, so the similarity score increases by 3 * 3 = 9.
-	The second number in the left list is 4. It appears in the right list once, so the similarity score increases by 4 * 1 = 4.
-	The third number in the left list is 2. It does not appear in the right list, so the similarity score does not increase (2 * 0 = 0).
-	The fourth number, 1, also does not appear in the right list.
-	The fifth number, 3, appears in the right list three times; the similarity score increases by 9.
-	The last number, 3, appears in the right list three times; the similarity score again increases by 9.
-
-So, for these example lists, the similarity score at the end of this process is 31 (9 + 4 + 0 + 0 + 9 + 9).
-
-Once again consider your left and right lists. What is their similarity score?
-
- */
 
 void day01::Calculate()
 {
@@ -124,7 +26,7 @@ void day01::Calculate()
 	col2.reserve(estimated_size);
 	occurrence_map.reserve(estimated_size);
 
-	std::ifstream input("input/day01.txt");
+	std::ifstream input("input/challenges.txt");
 
 	if (!input)
 	{

days/day02.cpp

@@ -4,54 +4,99 @@
 
 #include "day02.h"
 
-/*
+#include <fstream>
---- Day 2: Red-Nosed Reports ---
+#include <iostream>
-
+#include <iterator>
-Fortunately, the first location The Historians want to search isn't a long walk from the Chief Historian's office.
+#include <vector>
-
+#include <bits/fs_fwd.h>
-While the Red-Nosed Reindeer nuclear fusion/fission plant appears to contain no sign of the Chief Historian, the
+#include <bits/fs_path.h>
-engineers there run up to you as soon as they see you. Apparently, they still talk about the time Rudolph was saved
-through molecular synthesis from a single electron.
-
-They're quick to add that - since you're already here - they'd really appreciate your help analyzing some unusual data
-from the Red-Nosed reactor. You turn to check if The Historians are waiting for you, but they seem to have already
-divided into groups that are currently searching every corner of the facility. You offer to help with the unusual data.
-
-The unusual data (your puzzle input) consists of many reports, one report per line. Each report is a list of numbers
-called levels that are separated by spaces. For example:
-
-7 6 4 2 1
-1 2 7 8 9
-9 7 6 2 1
-1 3 2 4 5
-8 6 4 4 1
-1 3 6 7 9
-
-This example data contains six reports each containing five levels.
-
-The engineers are trying to figure out which reports are safe. The Red-Nosed reactor safety systems can only
-tolerate levels that are either gradually increasing or gradually decreasing. So, a report only counts as safe if
-both of the following are true:
-
-    The levels are either all increasing or all decreasing.
-    Any two adjacent levels differ by at least one and at most three.
-
-In the example above, the reports can be found safe or unsafe by checking those rules:
-
-    7 6 4 2 1: Safe because the levels are all decreasing by 1 or 2.
-    1 2 7 8 9: Unsafe because 2 7 is an increase of 5.
-    9 7 6 2 1: Unsafe because 6 2 is a decrease of 4.
-    1 3 2 4 5: Unsafe because 1 3 is increasing but 3 2 is decreasing.
-    8 6 4 4 1: Unsafe because 4 4 is neither an increase or a decrease.
-    1 3 6 7 9: Safe because the levels are all increasing by 1, 2, or 3.
-
-So, in this example, 2 reports are safe.
-
-Analyze the unusual data from the engineers. How many reports are safe?
-
- */
 
 void day02::Calculate()
 {
+	//std::ifstream input("input/day02short.txt");
+	std::ifstream input("input/day02.txt");
 
-}
+	if (!input)
+	{
+		std::cerr << "Failed to open input file." << std::endl;
+		std::cout << "Current path is " << std::filesystem::current_path() << '\n';
+
+		return;
+	}
+
+	int safeReports = 0;
+	for (std::string line; std::getline(input, line, '\n');)
+	{
+		std::istringstream iss(line);
+		std::vector numbers(std::istream_iterator<int>{iss}, std::istream_iterator<int>());
+		if (IsSafe(numbers, false))
+		{
+			safeReports++;
+		}
+	}
+	std::cout << safeReports << '\n';
+}
+
+bool day02::IsSafe(const std::vector<int> &numbers, const bool secondPass)
+{
+	int previousNumber = numbers.at(numbers.size() - 1);
+	bool increasing = false;
+	bool decreasing = false;
+	bool safe = true;
+	for (int i = numbers.size() - 2; i >= 0; i--)
+	{
+		const int currentNumber = numbers.at(i);
+
+		if (i == numbers.size() - 2)
+		{
+			if (previousNumber < currentNumber)
+			{
+				increasing = true;
+			}
+			if (previousNumber > currentNumber)
+			{
+				decreasing = true;
+			}
+		}
+
+		if (SafetyChecks(currentNumber, previousNumber, increasing, decreasing) == 1 && !secondPass)
+		{
+
+			if (IsSafe(numbers, true))
+			{
+				safe = false;
+				return false;
+			}
+		}
+
+		previousNumber = currentNumber;
+	}
+	if (safe)
+	{
+		return true;
+	}
+	return false;
+}
+
+int day02::SafetyChecks(const int current, const int previous, const bool increasing, const bool decreasing)
+{
+	const int diff = abs(current - previous);
+	if (previous > current && increasing)
+	{
+		return 1;
+	}
+	if (previous < current && decreasing)
+	{
+		return 1;
+	}
+	if (current == previous)
+	{
+		return 1;
+	}
+	if (diff < 1 || diff > 3)
+	{
+		return 1;
+	}
+	//safe
+	return 0;
+}

days/day02.h

@@ -4,12 +4,17 @@
 
 #ifndef DAY02_H
 #define DAY02_H
+#include <vector>
 
 
 class day02
 {
 public:
 	static void Calculate();
+
+	static bool IsSafe(const std::vector<int>& numbers,bool secondPass);
+
+	static int SafetyChecks(int current, int previous, bool increasing, bool decreasing);
 };
 
 #endif //DAY02_H

input/day02short.txt

@@ -0,0 +1,8 @@
+1 3 2 4 5
+8 6 4 4 1
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 6 7 9
+55 55 57 58 59 62 65 68
+22 25 27 28 30 31 32 29