public void Solve(Grid grid)
{
var boxCols = grid.GetBoxColumns();
var boxRows = grid.GetBoxRows();
for (var digit = 1; digit <= 9; ++digit)
{
for (var boxRow = 1; boxRow <= 3; ++boxRow)
{
var topRow = boxRows[boxRow].Item1;
var middleRow = boxRows[boxRow].Item1 + 1;
var bottomRow = boxRows[boxRow].Item2;
var possibleDigitRows = grid.FindThePotentialDigitInTheBoxRows(boxCols, digit, topRow, middleRow,
bottomRow);
if (possibleDigitRows.Values.All(v => v.Count != 1)) continue;
foreach (var possibleDigitRow in possibleDigitRows)
{
if (possibleDigitRow.Value.Count != 1) continue;
var rowToClear = possibleDigitRow.Value[0];
for (var otherBoxCol = 1; otherBoxCol <= 3; ++otherBoxCol)
{
if (otherBoxCol == possibleDigitRow.Key) continue;
for (var colIdx = boxCols[otherBoxCol].Item1;
colIdx <= boxCols[otherBoxCol].Item2;
++colIdx)
{
if (grid.Squares[rowToClear, colIdx].IsSolved) continue;
grid.Squares[rowToClear, colIdx].RemovePossibleDigit(digit);
}
}
}
}
}
}
