Implemented the functions

DigitSequence/DigitEnumerator.cs

@@ -4,31 +4,61 @@ namespace DigitSequence;
 
 public sealed class DigitEnumerator : IEnumerator<int>
 {
-    // TODO
-    //private readonly int _number;
+    private int _divisor;
+    private bool _started;
+    private readonly int _number;
 
+    /// <summary>
+    /// The constructor for <see cref="DigitEnumerator"/>
+    /// </summary>
+    /// <param name="number">The number</param>
     public DigitEnumerator(int number)
     {
-        // TODO
+        _number = Math.Abs(number);
     }
 
+    /// <summary>
+    /// Moves to the next position
+    /// Default is invalid
+    /// </summary>
+    /// <returns>True, if the move was successful, false otherwise</returns>
     public bool MoveNext()
     {
-        // TODO
-        return false;
+        if (!_started)
+        {
+            _started = true;
+            _divisor = (int)Math.Pow(10, (int)Math.Log10(_number));
+            return _divisor >= 0;
+        }
+    
+        _divisor /= 10;
+        return _divisor > 0;
     }
 
+    /// <summary>
+    /// Resets the current position
+    /// </summary>
     public void Reset()
     {
-        // TODO
+        _started = false;
+        _divisor = 0;
     }
 
-    public int Current => -1; // TODO
+    /// <summary>
+    /// Value of the current position
+    /// </summary>
+    public int Current => _divisor > 0 ? (_number / _divisor) % 10 : 0;
 
-    object IEnumerator.Current => null!; // TODO
+    /// <summary>
+    /// IEnumerator type for <seealso cref="Current"/>
+    /// </summary>
+    object IEnumerator.Current => Current;
 
+    /// <summary>
+    /// Disposes resources
+    /// </summary>
     public void Dispose()
     {
-        // TODO ?
+        // TODON'T! it doesn't seem that there is anything that has the need to be disposed
     }
 }