private static Position[] ReadFile(string fileName)
{
Position[] sudoku = new Position[9 * 9];
using (StreamReader input = new StreamReader(new FileStream(fileName, FileMode.Open)))
{
string line;
int lineCount = 0;
while ((line = input.ReadLine()) != null)
{
if (lineCount >= 9)
{
throw new Exception("More than 9 lines found in puzzle.");
}
if (line.Length != 9)
{
throw new Exception(String.Format("Line {0} is length {1}, expected 9.", lineCount, line.Length));
}
for (int i = 0; i < line.Length; ++i)
{
int num;
if (!int.TryParse(line[i].ToString(), out num))
{
throw new Exception(String.Format("Found non-integer in puzzle at line {0} pos {1}", lineCount, i));
}
sudoku[(lineCount * 9) + i] = new Position(num);
}
++lineCount;
}
return sudoku;
}
}
private static bool IsSolved(Position[] sudoku)
{
foreach (Position p in sudoku)
{
if (!p.IsSolved)
{
return false;
}
}
return true;
}
private static void SetColForPos(Position[] sudoku, int pos, int num)
{
int col = pos % 9;
for (int i = 0; i < 9; ++i)
{
int candidate = (i * 9) + col;
if (candidate != pos)
{
sudoku[candidate].RemovePossible(num);
}
}
}
private static void SetBlockForPos(Position[] sudoku, int pos, int num)
{
int startRow = RoundToThree(pos / 9);
int startCol = RoundToThree(pos % 9);
for (int row = startRow; row < startRow + 3; ++row)
{
for (int col = startCol; col < startCol + 3; ++col)
{
int candidate = (row * 9) + col;
if (candidate != pos)
{
sudoku[candidate].RemovePossible(num);
}
}
}
}
private static void SetRowForPos(Position[] sudoku, int pos, int num)
{
int row = pos / 9;
for (int i = 0; i < 9; ++i)
{
int candidate = (row * 9) + i;
if (candidate != pos)
{
sudoku[candidate].RemovePossible(num);
}
}
}
