feat: Add day 5

AdventOfCode2025/Day5.cs

@@ -0,0 +1,56 @@
+namespace AdventOfCode2025;
+
+public class Day5 : Solution
+{
+    public override string SolvePart1()
+    {
+        List<string> lines = InputReader.ReadLines(5).ToList();
+        List<Range> freshRanges = GetFreshRanges(lines);
+        int freshIngredients = lines[(freshRanges.Count + 1)..].Select(long.Parse).Count(id => IsFresh(id, freshRanges));
+        return freshIngredients.ToString();
+    }
+
+    public override string SolvePart2()
+    {
+        List<string> lines = InputReader.ReadLines(5).ToList();
+        List<Range> ranges = GetFreshRanges(lines).OrderBy(x => x.From).ThenBy(x => x.To).ToList();
+
+        var merged = new List<Range>();
+        Range current = ranges[0];
+
+        for (var i = 1; i < ranges.Count; i++)
+        {
+            Range next = ranges[i];
+
+            if (next.From <= current.To)
+            {
+                current.To = Math.Max(current.To, next.To);
+            }
+            else
+            {
+                merged.Add(current);
+                current = next;
+            }
+        }
+
+        merged.Add(current);
+
+        return merged.Sum(r => r.To - r.From + 1).ToString();
+    }
+
+    private static List<Range> GetFreshRanges(List<string> lines) => lines
+        .TakeWhile(line => !string.IsNullOrEmpty(line))
+        .Select(range => range.Split('-').Select(long.Parse).ToArray())
+        .Select(v => new Range(v))
+        .ToList();
+
+    private static bool IsFresh(long id, IEnumerable<Range> ranges) => ranges.Any(range => IsFresh(id, range));
+
+    private static bool IsFresh(long id, Range range) => id >= range.From && id <= range.To;
+
+    private sealed class Range(long[] values)
+    {
+        public long From { get; } = values[0];
+        public long To { get; set; } = values[1];
+    }
+}

AdventOfCode2025/Inputs/Day5_0.txt

@@ -0,0 +1,11 @@
+3-5
+10-14
+16-20
+12-18
+
+1
+5
+8
+11
+17
+32