Code cleanup, reduced duplication.

Author: kurtanr

SimpleSudokuSolver.Tests/Strategy/LockedCandidatesPointingTests.cs

@@ -36,34 +36,6 @@ public void LockedCandidatesPointingInColumnTest()
       CollectionAssert.DoesNotContain(sudokuPuzzle.Cells[8, 0].CanBe, 3);
     }
 
-    [Test]
-    public void LockedCandidatesPointingInRowTest()
-    {
-      // From: https://sudoku9x9.com/locked_candidates.html, transposed
-      var sudoku = new[,]
-      {
-        { 0,0,0,0,0,0,0,0,0 },
-        { 1,0,5,0,0,0,0,0,0 },
-        { 2,0,6,0,0,0,0,0,0 },
-        { 0,0,0,0,0,0,0,0,0 },
-        { 0,0,0,0,0,0,0,0,0 },
-        { 0,3,0,0,0,0,0,0,0 },
-        { 0,0,0,0,0,0,0,0,0 },
-        { 0,0,0,0,0,0,0,0,0 },
-        { 0,0,0,0,0,0,0,0,0 }
-      };
-
-      var sudokuPuzzle = new SudokuPuzzle(sudoku);
-      SolveUsingStrategy(sudokuPuzzle, _strategy);
-
-      CollectionAssert.DoesNotContain(sudokuPuzzle.Cells[0, 3].CanBe, 3);
-      CollectionAssert.DoesNotContain(sudokuPuzzle.Cells[0, 4].CanBe, 3);
-      CollectionAssert.DoesNotContain(sudokuPuzzle.Cells[0, 5].CanBe, 3);
-      CollectionAssert.DoesNotContain(sudokuPuzzle.Cells[0, 6].CanBe, 3);
-      CollectionAssert.DoesNotContain(sudokuPuzzle.Cells[0, 7].CanBe, 3);
-      CollectionAssert.DoesNotContain(sudokuPuzzle.Cells[0, 8].CanBe, 3);
-    }
-
     [Test]
     public void LockedCandidatesPointingTest1()
     {

SimpleSudokuSolver/Strategy/LockedCandidatesClaiming.cs

@@ -91,11 +91,8 @@ private IEnumerable<Tuple<Cell, int>> GetCellCandidatePairsWhichAppearOnlyInSing
       foreach (var item in candidateValuesWhichAppearOnlyInSingleBlock)
       {
         // We could return all the cells, but just one is enough to eliminate other candidates
-        var cellOrNull = cellsWithNoValue.Where(x => x.CanBe.Contains(item)).FirstOrDefault();
-        if (cellOrNull != null)
-        {
-          result.Add(new Tuple<Cell, int>(cellOrNull, item));
-        }
+        var cell = cellsWithNoValue.First(x => x.CanBe.Contains(item));
+        result.Add(new Tuple<Cell, int>(cell, item));
       }
 
       return result;