feat(*): Add 2021-10 part 1 files

2026-07-12 18:53:47 +00:00 · 2021-12-10 11:17:57 +00:00
parent 15ce3f28ad
commit f5937d3fd7
5 changed files with 274 additions and 0 deletions
@@ -0,0 +1,95 @@
+namespace Day10
+{
+    class Program
+    {
+        static List<char> openingCharacters = new List<char>() { '(', '[', '{', '<' };
+        static List<char> closingCharacters = new List<char>() { ')', ']', '}', '>' };
+
+        static void Main(string[] args)
+        {
+            string[] lines = File.ReadAllLines("input.txt");
+
+
+            Part1(lines);
+            //Part2(lines);
+        }
+
+        static void Part1(string[] lines)
+        {
+            List<string> uncorruptedLines = new List<string>();
+            int syntaxErrorScore = 0;
+
+            foreach (string line in lines)
+            {
+                if (!IsLineCorrupted(line, ref syntaxErrorScore))
+                {
+                    uncorruptedLines.Add(line);
+                }
+            }
+
+            Console.WriteLine($"Syntax error score: {syntaxErrorScore}");
+        }
+
+        static bool IsLineCorrupted(string line, ref int syntaxErrorScore)
+        {
+            Stack<char> stackOfExpectedClosingCharacters = new Stack<char>();
+
+            for (int i = 0; i < line.Length; i++)
+            {
+                if (openingCharacters.Contains(line[i]))
+                {
+                    // If it's an opening character then add the expected closing character to the stack
+                    stackOfExpectedClosingCharacters.Push(GetExpectedClosingCharacter(line[i]));
+                }
+                else if (closingCharacters.Contains(line[i]))
+                {
+                    // If it's a closing character, then check if it's the one we're expecting
+                    // Make sure there's items in the stack so we don't get an InvalidOperationException
+                    if (stackOfExpectedClosingCharacters.Count > 0)
+                    {
+                        char expectedClosingCharacter = stackOfExpectedClosingCharacters.Pop();
+                        if (line[i] != expectedClosingCharacter)
+                        {
+                            // It's not the one we're expecting so the line is corrupted
+                            Console.WriteLine($"Expected {expectedClosingCharacter}, but found {line[i]} instead.");
+
+                            // Update the syntax error score
+                            switch (line[i])
+                            {
+                                case ')':
+                                    syntaxErrorScore += 3;
+                                    break;
+                                case ']':
+                                    syntaxErrorScore += 57;
+                                    break;
+                                case '}':
+                                    syntaxErrorScore += 1197;
+                                    break;
+                                case '>':
+                                    syntaxErrorScore += 25137;
+                                    break;
+                                default:
+                                    break;
+                            }
+
+                            // Report the corrupted line
+                            return true;
+                        }
+
+                        // If it is the one we're expecting we can safely carry on with the line
+                    }
+                }
+            }
+
+            // Having reached the end of the line with no wrong closing characters the line cannot be corrupted
+            return false;
+        }
+
+        static char GetExpectedClosingCharacter(char openingCharacter)
+        {
+            int index = openingCharacters.FindIndex(x => x == openingCharacter);
+
+            return closingCharacters[index];
+        }
+    }
+}