edit

MatrixExtensions.csproj

@@ -72,6 +72,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="MatrixExtensions.cs" />
+    <Compile Include="MatrixL.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="Utilites.cs" />
   </ItemGroup>

MatrixL.cs

@@ -0,0 +1,118 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace MatrixExtensions
+{
+   public class MatrixL<T>
+   {
+      List<List<T>> src;
+      T init;
+      int r;
+      int c;
+
+      public MatrixL(int r, int c, T initValue)
+      {
+         this.r = r;
+         this.c = c;
+         init = initValue;
+         src = new List<List<T>>(r);
+         for (int i = 0; i < r; i++)
+         {
+            src.Add(new List<T>(c));
+            for (int j = 0; j < c; j++)
+            {
+               src[i].Add(initValue);
+            }
+         }
+      }
+
+      public T GetEl(int idxR, int idxC)
+      {
+         return src[idxR][idxC];
+      }
+
+      public void SetEl(int idxR, int idxC, T el)
+      {
+         src[idxR][idxC] = el;
+      }
+
+      public void InsertRow(int idxR)
+      {
+         if (idxR > r) return;
+
+         src.Insert(idxR, new List<T>(c));
+         r++;
+         for (int i = 0; i < c; i++)
+         {
+            src[idxR].Add(init);
+         }
+      }
+
+      public void InsertRow(int idxR, List<T> row)
+      {
+         if (idxR > r) return;
+
+         src.Insert(idxR, new List<T>(c));
+         r++;
+         int n = c;
+         if (row.Count < c) n = row.Count;
+
+         for (int i = 0; i < n; i++)
+         {
+            src[idxR].Add(row[i]);
+         }
+
+         if (row.Count < c)
+         {
+            for (int i = n; i < c; i++)
+            {
+               src[idxR].Add(init);
+            }
+         }
+      }
+      
+      public void InsertCol(int idxC)
+      {
+         if (idxC > c) return;
+
+         c++;
+         for (int i = 0; i < r; i++)
+         {
+            src[i].Insert(idxC, init);
+         }
+      }
+
+      public void InsertCol(int idxC, List<T> col)
+      {
+         if (idxC > c) return;
+
+         c++;
+         for (int i = 0; i < r; i++)
+         {
+            src[i].Insert(idxC, init);
+         }
+
+         int n = r;
+         if (col.Count < r) n = col.Count;
+
+         foreach (List<T> item in src)
+         {
+            for (int i = 0; i < n; i++)
+            {
+               item.Insert(idxC, col[i]);
+            }
+            if (col.Count < r)
+            {
+               for (int i = n; i < r; i++)
+               {
+                  item.Insert(idxC, init);
+               }
+            }
+         }
+      }
+
+   }
+}