diff --git a/.idea/.idea.EndMove.Sudoku.Solver/.idea/encodings.xml b/.idea/.idea.EndMove.Sudoku.Solver/.idea/encodings.xml
deleted file mode 100644
index df87cf9..0000000
--- a/.idea/.idea.EndMove.Sudoku.Solver/.idea/encodings.xml
+++ /dev/null
@@ -1,4 +0,0 @@
-
-
-
-
\ No newline at end of file
diff --git a/EndMove.Sudoku.Solver.sln b/EndMove.Sudoku.Solver.sln
index 78ca8d3..1d1fd2b 100644
--- a/EndMove.Sudoku.Solver.sln
+++ b/EndMove.Sudoku.Solver.sln
@@ -1,4 +1,4 @@
-
+
Microsoft Visual Studio Solution File, Format Version 12.00
Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{67AA5CD2-BE13-4741-8F70-4FE3638271E4}"
EndProject
diff --git a/src/EndMove.Sudoku.Solver.Core/Algorithms/BackTrackingSolver.cs b/src/EndMove.Sudoku.Solver.Core/Algorithms/BackTrackingSolver.cs
index c3fe046..2c8fead 100644
--- a/src/EndMove.Sudoku.Solver.Core/Algorithms/BackTrackingSolver.cs
+++ b/src/EndMove.Sudoku.Solver.Core/Algorithms/BackTrackingSolver.cs
@@ -1,9 +1,15 @@
-namespace EndMove.Sudoku.Solver.Core.Algorithms;
+namespace EndMove.Sudoku.Solver.Core.Algorithms;
public class BackTrackingSolver : SolverBase
{
public BackTrackingSolver(Action displayBoard) : base(displayBoard) { }
+ /**
+ * note for future me :
+ * - Maybe pre-process the board to get the empty cells and already know used values per row, col and box
+ * - Maybe keep a track of the current index to avoid searching for the next empty cell in the all 2d array
+ * - Maybe avoid using negation
+ */
public override (bool, int[,]) Solve(int[,] board)
{
int row = -1, col = -1;
diff --git a/src/EndMove.Sudoku.Solver.Core/Program.cs b/src/EndMove.Sudoku.Solver.Core/Program.cs
index e6f0f2c..03c8bc2 100644
--- a/src/EndMove.Sudoku.Solver.Core/Program.cs
+++ b/src/EndMove.Sudoku.Solver.Core/Program.cs
@@ -58,7 +58,9 @@ namespace EndMove.Sudoku.Solver.Core
SudokuUtils.TwoDTo1D(store[0], out int[] sudoku1D);
SudokuUtils.DisplayBoard(sudoku1D);
+ // TODO improve 2D backtracking solver
// TODO 1D solver with backtracking
+ // TODO Add time measurement
ISolver solver = new BackTrackingSolver(SudokuUtils.DisplayBoard);
var (status, lol) = solver.Solve(store[0]);