public bool Equals(SudokuGrid obj)
{
for (int row = 0; row < 9; row++)
{
for (int column = 0; column < 9; column++)
{
if (!this[row, column].Equals(obj[row, column]))
{
return(false);
}
}
}
return(true);
}
/// <summary>
/// Checks whether a given SudokuGrid is valid
/// </summary>
/// <returns></returns>
public bool IsValid()
{
SudokuSolver sudokuSolver = new SudokuSolver();
SudokuGrid mySudoku = sudokuSolver.Copy(this);
if (sudokuSolver.IsSolved(this))
{
return(true);
}
if (this.NumSolved() < 16)
{
return(false);
}
mySudoku.SolveForIsValid();
//if simple solve, return is valid
if (sudokuSolver.IsSolved(mySudoku))
{
return(true);
}
bool solvedOne = false;
SudokuGrid copy1 = sudokuSolver.Copy(this);
sudokuSolver.bruteForceSolver(ref copy1);
if (!sudokuSolver.IsSolved(copy1))
{
return(false);
}
if (sudokuSolver.InvalidMove(this))
{
return(false);
}
SudokuGrid firstSolve = new SudokuGrid();
firstSolve = sudokuSolver.Copy(copy1);
//else, guess all possibles and brute force solve. if multiple solutions, return false
for (int row = 0; row < 9; row++)
{
for (int column = 0; column < 9; column++)
{
//if unsolved
if (!this[row, column].getSolved())
{
for (int i = 0; i < this[row, column].getPossibles().Count; i++)
{
SudokuGrid copy = sudokuSolver.Copy(this);
//solve to the index of the guess
copy[row, column].solve(copy[row, column].getPossibles()[i]);
bool solvedThisOne;
try
{
//brute force it
sudokuSolver.bruteForceSolver(ref copy);
solvedThisOne = sudokuSolver.IsSolved(copy);
}
catch
{
solvedThisOne = false;
}
//if this one and another different one were solved, invalid for too many solutions
if (solvedThisOne)
{
try
{
if (!firstSolve.ToString().Equals(copy.ToString()))
{
//return false;
}
if (!sudokuSolver.Equals(firstSolve, copy))
{
return(false);
}
}
catch
{
}
}
if (solvedThisOne)
{
firstSolve = sudokuSolver.Copy(copy);
}
}
}
}
}
return(true);
}