feat: solved day 2 part 1...part 2 is WIP

02/RedNosedReports/Report.cs

@@ -0,0 +1,81 @@
+namespace RedNosedReports;
+
+class Report(List<int> levels)
+{
+  private readonly List<int> _levels = levels;
+
+  public bool IsSafe()
+  {
+    for (var i = 0; i < _levels.Count - 1; i++)
+    {
+      if (CheckIfSafe(_levels[i], _levels[i + 1]) is false)
+      {
+        return false;
+      }
+    }
+
+    return true;
+  }
+
+  public bool IsSafeWithProblemDampener()
+  {
+    for (var currentIndex = 0; currentIndex < _levels.Count - 1; currentIndex++)
+    {
+      var nextIndex = currentIndex + 1;
+      var current = _levels[currentIndex];
+      var next = _levels[nextIndex];
+
+      if (CheckIfSafe(current, next) is false)
+      {
+        var levelsWithoutCurrent = _levels.ToList();
+        levelsWithoutCurrent.RemoveAt(currentIndex);
+        var isSafeWithoutCurrent = new Report(levelsWithoutCurrent).IsSafe();
+
+        if (isSafeWithoutCurrent)
+        {
+          return true;
+        }
+
+        var levelsWithoutNext = _levels.ToList();
+        levelsWithoutNext.RemoveAt(nextIndex);
+        var isSafeWithoutNext = new Report(levelsWithoutNext).IsSafe();
+
+        if (isSafeWithoutNext)
+        {
+          return true;
+        }
+
+        return false;
+      }
+    }
+
+    return true;
+  }
+
+  private bool CheckIfSafe(int current, int next)
+  {
+    var direction = _levels[1] > _levels[0]
+      ? Direction.Increasing
+      : Direction.Decreasing;
+
+    var isNextGreaterThanCurrent = next > current;
+    var delta = Math.Abs(next - current);
+
+    if (delta > 3 || delta < 1)
+    {
+      return false;
+    }
+
+    if (direction is Direction.Increasing && isNextGreaterThanCurrent is false)
+    {
+      return false;
+    }
+
+    if (direction is Direction.Decreasing && isNextGreaterThanCurrent)
+    {
+      return false;
+    }
+
+    return true;
+  }
+}