public (bool, List <int>) Solve()
{
char[] SolveGrid(char[] Board)
{
bool altered = true;
List <(int, List <int>)> ops = FindSquareOptions(Board);
int index;
try
{
index = ops.FindIndex(i => i.Item2.Count == ops.Select(j => j.Item2.Count).Where(k => k > 0).Min());
}
catch (Exception)
{
return(new List <char>(Board).ToArray());
}
if (index < 0)
{
return(new List <char>(Board).ToArray());
}
while (altered)
{
if (ops.Count <= 0)
{
return(new List <char>(Board).ToArray());
}
if (ops[index].Item2.Count == 1)
{
Board[ops[index].Item1] = (char)(ops[index].Item2.First() + 48);
ops = FindSquareOptions(Board);
try
{
index = ops.FindIndex(i =>
i.Item2.Count == ops.Select(j => j.Item2.Count).Where(k => k > 0).Min());
}
catch (Exception)
{
new List <char>(Board).ToArray();
}
continue;
}
altered = false;
foreach (var square in sqIndices)
{
List <(int, List <int>)> sqOps = new List <(int, List <int>)>();
foreach (var tile in square)
{
sqOps.Add(ops[tile]);
}
Dictionary <int, int> sqOpCounts = new Dictionary <int, int>();
foreach (var opList in sqOps)
{
foreach (var num in opList.Item2)
{
if (sqOpCounts.ContainsKey(num))
{
sqOpCounts[num] += 1;
}
else
{
sqOpCounts.Add(num, 1);
}
}
}
foreach (var pair in sqOpCounts)
{
if (pair.Value == 1)
{
foreach (var opList in sqOps)
{
if (opList.Item2.Contains(pair.Key))
{
Board[opList.Item1] = (char)(pair.Key + 48);
ops = FindSquareOptions(Board);
try
{
index = ops.FindIndex(i =>
i.Item2.Count == ops.Select(j => j.Item2.Count).Where(k => k > 0)
.Min());
}
catch (Exception)
{
new List <char>(Board).ToArray();
}
altered = true;
}
}
}
}
}
}
return(new List <char>(Board).ToArray());
}
char[] originalGrid = board.GetBoard();
char[] sBoard = SolveGrid(new List <char>(originalGrid).ToArray());
List <int> added = new List <int>();
if (check.CheckBoard(sBoard).Item1)
{
for (int i = 0; i < 81; i++)
{
if (originalGrid[i] != sBoard[i])
{
added.Add(i);
}
}
board.SetBoard(sBoard);
return(true, added);
}
if (!check.CheckBoard(sBoard, true).Item1)
{
return(false, added);
}
char[] testBoard = new List <char>(sBoard).ToArray();
List <(int, List <int>)> options = FindSquareOptions(sBoard);
List <List <(int, List <int>)> > testOptions = new List <List <(int, List <int>)> >();
List <int> indices = new List <int>();
List <char[]> boards = new List <char[]>();
testOptions.Add(options);
indices.Add(options.FindIndex(i => i.Item2.Count == options.Select(j => j.Item2.Count).Where(k => k > 0).Min()));
boards.Add(testBoard);
bool CheckOptions()
{
if (check.CheckFull(boards[^ 1]))