Сравнение объектов.

Warship/Warship/DrawingObjectWarship.cs

@@ -33,5 +33,32 @@ namespace AircraftCarrier
         }
         public string GetInfo() => _warship?.GetDataForSave();
         public static IDrawingObject Create(string data) => new DrawingObjectWarship(data.CreateDrawingWarship());
+        public bool Equals(IDrawingObject? other)
+        {
+            if (other is not DrawingObjectWarship otherWarship)
+            {
+                return false;
+            }
+            var warship = _warship.Ship;
+            var otherEntity = otherWarship._warship.Ship;
+            if (warship.GetType() != otherEntity.GetType() ||
+                warship.Speed != otherEntity.Speed ||
+                warship.Weight != otherEntity.Weight ||
+                warship.BodyColor != otherEntity.BodyColor)
+            {
+                return false;
+            }
+
+            if (warship is EntityPlaneWarship entityPlaneWarship &&
+                otherEntity is EntityPlaneWarship otherEntityPlaneWarship && (
+                entityPlaneWarship.BodyKit != otherEntityPlaneWarship.BodyKit ||
+                entityPlaneWarship.СontrolPlace != otherEntityPlaneWarship.СontrolPlace ||
+                entityPlaneWarship.RunWay != otherEntityPlaneWarship.RunWay ||
+                entityPlaneWarship.DopColor != otherEntityPlaneWarship.DopColor))
+            {
+                return false;
+            }
+            return true;
+        }
     }
 }

Warship/Warship/IDrawingObject.cs

@@ -9,7 +9,7 @@ namespace AircraftCarrier
     /// <summary>
     /// Интерфейс для работы с объектом, прорисовываемым на форме
     /// </summary>
-    internal interface IDrawingObject
+    internal interface IDrawingObject : IEquatable<IDrawingObject>
     {
         /// <summary>
         /// Шаг перемещения объекта

Warship/Warship/MapWithSetWarshipGeneric.cs

@@ -12,7 +12,7 @@ namespace AircraftCarrier
     /// <typeparam name="T"></typeparam>
     /// <typeparam name="U"></typeparam>
     internal class MapWithSetWarshipsGeneric<T, U>
-        where T : class, IDrawingObject
+        where T : class, IDrawingObject, IEquatable<T>
         where U : AbstractMap
     {
         /// <summary>

Warship/Warship/SetWarshipGeneric.cs

@@ -11,7 +11,7 @@ namespace AircraftCarrier
     /// </summary>
     /// <typeparam name="T"></typeparam>
     internal class SetWarshipsGeneric<T>
-        where T : class
+        where T : class, IEquatable<T>
     {
         /// <summary>
         /// Список объектов, которые храним
@@ -53,6 +53,8 @@ namespace AircraftCarrier
         /// <returns></returns>
         public int Insert(T ship, int position)
         {
+            if (_places.Contains(ship))
+                return -1;
             if (Count == _maxCount)
                 throw new StorageOverflowException(_maxCount);
             if (!isCorrectPosition(position))
@@ -107,6 +109,18 @@ namespace AircraftCarrier
                 }
             }
         }
+        /// <summary>
+		/// Сортировка набора объектов
+		/// </summary>
+		/// <param name="comparer"></param>
+		public void SortSet(IComparer<T> comparer)
+        {
+            if (comparer == null)
+            {
+                return;
+            }
+            _places.Sort(comparer);
+        }
     }
 }