Первый шаг готов

SelfPropelledArtilleryUnit/DrawingObjectArtillery.cs

@@ -40,5 +40,63 @@ namespace Artilleries
         public string GetInfo() => _artillery?.GetDateForSave();
 
         public static IDrawingObject Create(string data) => new DrawingObjectArtillery(data.CreateDrawingArtillery());
+    
+        public bool Equals(IDrawingObject? other)
+        {
+            if (other == null)
+            {
+                return false;
+            }
+
+            var otherArtillery = other as DrawingObjectArtillery;
+
+            if (otherArtillery == null)
+            {
+                return false;
+            }
+
+            var artillery = _artillery.Artillery;
+            var otherArtilleryArtillery = otherArtillery._artillery.Artillery;
+        
+            if (artillery.GetType() != otherArtilleryArtillery.GetType())
+            {
+                return false;
+            }
+            
+            if (artillery.Speed != otherArtilleryArtillery.Speed)
+            {
+                return false;
+            }
+
+            if (artillery.Weight != otherArtilleryArtillery.Weight)
+            {
+                return false;
+            }
+
+            if (artillery.BodyColor != otherArtilleryArtillery.BodyColor)
+            {
+                return false;
+            }
+
+            if (artillery is EntityAdvancedArtillery advanced && otherArtilleryArtillery is EntityAdvancedArtillery otherAdvanced)
+            {
+                if (advanced.DopColor != otherAdvanced.DopColor)
+                {
+                    return false;
+                }
+
+                if (advanced.Weapon != otherAdvanced.Weapon)
+                {
+                    return false;
+                }
+
+                if (advanced.SalvoBattery != otherAdvanced.SalvoBattery)
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
     }
 }

SelfPropelledArtilleryUnit/IDrawingObject.cs

@@ -6,7 +6,7 @@ using System.Threading.Tasks;
 
 namespace Artilleries
 {
-    internal interface IDrawingObject
+    internal interface IDrawingObject : IEquatable<IDrawingObject>
     {
         public float Step { get; }
         void SetObject(int x, int y, int width, int height);

SelfPropelledArtilleryUnit/SetArtilleriesGeneric.cs

@@ -7,7 +7,7 @@ using System.Threading.Tasks;
 namespace Artilleries
 {
     internal class SetArtilleriesGeneric<T>
-        where T : class
+        where T : class, IEquatable<T>
     {
         private readonly List<T> _places;
         public int Count => _places.Count;
@@ -36,6 +36,11 @@ namespace Artilleries
                 return -1;
             }
 
+            if (_places.Contains(artillery))
+            {
+                return -1;
+            }
+
             _places.Insert(position, artillery);
 
             return position;