Added Day5 and started adding test input txt files.

Advent24/Day5.cs

@@ -0,0 +1,195 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection.Emit;
+using System.Text;
+using System.Threading.Tasks;
+using System.Text.RegularExpressions;
+
+namespace Advent24
+{
+    internal class Day5
+    {
+        private static void IngestRule(String rule, Dictionary<Int32, List<(Int32, Int32)>> ruleDict)
+        {
+            var ruleArray = rule.Split('|');
+            
+            var ruleArrayInt32 = Array.ConvertAll(ruleArray, System.Convert.ToInt32);
+
+            // if the ruleDict index doesn't already exists, add an empty list to it
+            ruleDict.TryAdd(ruleArrayInt32[0], new List<(int, int)>(2));
+            ruleDict[ruleArrayInt32[0]].Add((ruleArrayInt32[0], ruleArrayInt32[1]));
+
+            ruleDict.TryAdd(ruleArrayInt32[1], new List<(int, int)>(2));
+            ruleDict[ruleArrayInt32[1]].Add((ruleArrayInt32[0], ruleArrayInt32[1]));
+        }
+
+        private static void IngestPageRow(String pageRow, List<Dictionary<Int32, Int32>> pageRowDictsList)
+        {
+            var pageRowArray = pageRow.Split(',');
+
+            var pageRowArrayInt32 = Array.ConvertAll(pageRowArray, System.Convert.ToInt32);
+
+            pageRowDictsList.Add(new Dictionary<Int32, Int32>(pageRowArray.Length));
+
+            Int32 pageRowIndex = 1;
+
+            foreach (var pageInt32 in pageRowArrayInt32)
+            {
+                pageRowDictsList[pageRowDictsList.Count - 1].Add(pageInt32, pageRowIndex);
+
+                pageRowIndex++;
+            }
+        }
+
+        private static Int32 GetPageRowMiddle(Dictionary<Int32, Int32> pageRowDict)
+        {
+            var pageRowMiddleEnumerable = pageRowDict.Where(keyValuePair => keyValuePair.Value == (pageRowDict.Count + 1) / 2);
+            
+            return pageRowMiddleEnumerable.ElementAt(0).Key;
+        }
+
+        private static Boolean PageRowIsCorrect(Dictionary<Int32, Int32> pageRowDict, Dictionary<Int32, List<(Int32, Int32)>> ruleDict)
+        {
+            Boolean pageRowIsCorrect = true;
+
+            foreach(Int32 page in pageRowDict.Keys)
+            {
+                if (ruleDict.TryGetValue(page, out List<(int, int)>? rules))
+                {
+                    foreach (var rule in rules)
+                    {
+                        // check if the rule pertains to our pageRow
+                        if(pageRowDict.TryGetValue(rule.Item1, out Int32 leftHandIndex) &&
+                            pageRowDict.TryGetValue(rule.Item2, out Int32 rightHandIndex))
+                            // if rule violation detected, set pageRowIsCorrect to false
+                            // and break as we don't need to check the rest of the pageRow
+                            if (leftHandIndex >= rightHandIndex)
+                            {
+                                pageRowIsCorrect = false;
+                                break;
+                            }
+                    }
+
+                    // break out of outer foreach loop if nner foreach
+                    // was broken due to finding a rule violation
+                    if (!pageRowIsCorrect) break;
+                }
+            }
+
+            return pageRowIsCorrect;
+        }
+
+        private static Int32 GetCorrectMiddlesSum(Dictionary<Int32, List<(Int32, Int32)>> ruleDict, List<Dictionary<Int32, Int32>> pageRowDictsList)
+        {
+            Int32 correctMiddlesSum = 0;
+
+            foreach (var pageRowDict in pageRowDictsList)
+            {
+                if (PageRowIsCorrect(pageRowDict, ruleDict))
+                {
+                    correctMiddlesSum += GetPageRowMiddle(pageRowDict);
+                }
+            }
+            return correctMiddlesSum;
+        }
+
+        private static void CorrectPageRow(out Dictionary<Int32, Int32> correctedPageRowDict, Dictionary<Int32, Int32> pageRowDict, Dictionary<Int32, List<(Int32, Int32)>> ruleDict)
+        {
+            correctedPageRowDict = pageRowDict.ToDictionary();
+
+            Boolean correctionWasRequired;
+
+            do
+            {
+                correctionWasRequired = false;
+                foreach (Int32 page in pageRowDict.Keys)
+                {
+                    if (ruleDict.TryGetValue(page, out List<(int, int)>? rules))
+                    {
+                        foreach (var rule in rules)
+                        {
+                            // check if the rule pertains to our pageRow
+                            if (correctedPageRowDict.TryGetValue(rule.Item1, out Int32 leftHandIndex) &&
+                                correctedPageRowDict.TryGetValue(rule.Item2, out Int32 rightHandIndex))
+                                // if rule violation detected, swap the positions
+                                if (leftHandIndex >= rightHandIndex)
+                                {
+                                    // swap indices, i.e., swap positions
+                                    correctedPageRowDict[rule.Item1] = rightHandIndex;
+                                    correctedPageRowDict[rule.Item2] = leftHandIndex;
+
+                                    correctionWasRequired = true;
+                                }
+                        }
+                    }
+                }
+            } while(correctionWasRequired);
+        }
+
+        private static Int32 GetCorrectedMiddlesSum(Dictionary<Int32, List<(Int32, Int32)>> ruleDict, List<Dictionary<Int32, Int32>> pageRowDictsList)
+        {
+            Int32 correctMiddlesSum = 0;
+
+            foreach (var pageRowDict in pageRowDictsList)
+            {
+                if (!PageRowIsCorrect(pageRowDict, ruleDict))
+                {
+                    CorrectPageRow(out Dictionary<int, int> correctedPageRowDict, pageRowDict, ruleDict);
+                    correctMiddlesSum += GetPageRowMiddle(correctedPageRowDict);
+                }
+            }
+            return correctMiddlesSum;
+        }
+
+        public Day5()
+        {
+            String fileData = System.IO.File.ReadAllText(@"..\..\..\inputd5.txt");
+
+            var rulesAndPageRowsArray = fileData.Split('\n');
+
+            // indicates when we stop ingesting rules and start ingesting page rows
+            Boolean amIngestingRules = true;
+
+            // a dictionary to map from a page number to a rule containing that page number
+            // the rule is that p1 must appear before p2 if the Tuple is (p1, p2), i.e., 
+            // index of p1 must be less than index of p2
+            Dictionary<Int32, List<(Int32, Int32)>> ruleDict = [];
+
+            // a dictionary to map from a page number to its position in the array
+            List<Dictionary<Int32, Int32>> pageRowDictsList = [];
+
+            Int32 sumOfCorrectMiddles;
+            Int32 sumOfCorrectedMiddles;
+
+            foreach (var ruleOrPageRow in rulesAndPageRowsArray)
+            {
+                // empty line indicates end of rules and beginning of page rows
+                if (ruleOrPageRow == "")
+                {
+                    amIngestingRules = false;
+                    continue;
+                }
+
+                if(amIngestingRules)
+                {
+                    IngestRule(ruleOrPageRow, ruleDict);
+                }
+                else
+                {
+                    // am ingesting page rows now
+                    IngestPageRow(ruleOrPageRow, pageRowDictsList);
+                }
+            }
+
+            sumOfCorrectMiddles = GetCorrectMiddlesSum(ruleDict, pageRowDictsList);
+            sumOfCorrectedMiddles = GetCorrectedMiddlesSum(ruleDict, pageRowDictsList);
+
+            Console.WriteLine("sumOfCorrectMiddles = {0:d}", sumOfCorrectMiddles);
+            Console.WriteLine("sumOfCorrectedMiddles = {0:d}", sumOfCorrectedMiddles);
+
+            // to keep the console window from closing
+            Console.ReadKey();
+        }
+    }
+}

Advent24/Program.cs

@@ -9,8 +9,9 @@ namespace Advent24
         {
             //_ = new Day1();
             //_ = new Day2();
-            // _ = new Day3();
+            //_ = new Day3();
-            _ = new Day4();
+            //_ = new Day4();
+            _ = new Day5();
         }
     }
 }

Advent24/inputd5test.txt

@@ -0,0 +1,28 @@
+47|53
+97|13
+97|61
+97|47
+75|29
+61|13
+75|53
+29|13
+97|29
+53|29
+61|53
+97|53
+61|29
+47|13
+75|47
+97|75
+47|61
+75|61
+47|29
+75|13
+53|13
+
+75,47,61,53,29
+97,61,53,29,13
+75,29,13
+75,97,47,61,53
+61,13,29
+97,13,75,29,47