Added FlexArrayInt and created FlexArrayString.cs

FlexArray/FlexArrayInt.cs

@@ -0,0 +1,110 @@
+namespace FlexArray;
+
+public sealed class FlexArrayInt
+{
+    public const int DefaultStartSize = 4;
+    private int[] _data;
+    
+    public int Count { get; private set; }
+    public int Capacity => _data.Length;
+
+    public int this[int index]
+    {
+        get
+        {
+            if (index < 0 || index > Count)
+            {
+                return -1;
+            }
+
+            return _data[index];
+        }
+    }
+
+    public bool Remove(int value, bool firstOnly)
+    {
+        var removedAny = false;
+        for (var i = 0; i < Count; i++)
+        {
+            if (value != _data[i])
+            {
+                continue;
+            }
+
+            RemoveAt(i--);
+            removedAny = true;
+            if (firstOnly)
+            {
+                break;
+            }
+        }
+
+        return removedAny;
+    }
+
+    public bool RemoveAt(int index)
+    {
+        if (index < 0 || index >= Count)
+        {
+            return false;
+        }
+
+        if (index != Count - 1)
+        {
+            ShiftLeft(index);
+            
+        }
+
+        Count--;
+
+        return true;
+    }
+
+    private void ShiftLeft(int fromIndex)
+    {
+        for (var i = fromIndex; i < Count; i++)
+        {
+            _data[i] = _data[i + 1];
+        }
+    }
+    public FlexArrayInt(int? initialSize = null)
+    {
+        var size = Math.Max(0, initialSize ?? DefaultStartSize);
+        _data = new int[size];
+    }
+
+    public void Add(int value)
+    {
+        if (Capacity == Count)
+        {
+            Grow();
+        }
+
+        _data[Count++] = value;
+    }
+
+    public bool Contains(int value)
+    {
+        if (Count == 0)
+        {
+            return false;
+        }
+
+        for (var i = 0; i < Count; i++)
+        {
+            if (_data[i] == value)
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+    private void Grow()
+    {
+        var newData = new int[Capacity * 2];
+        Array.Copy(_data, newData, Count);
+        _data = newData;
+
+    }
+}