/// <summary>
/// Color the puzzle according to the "Test" value of the cell
/// </summary>
/// <param name="mode">Solve mode colors the whole puzzle, while hint mode colors only one cell</param>
private void ColorTest(SolvingMode mode)
{
for (int i = 0; i < SizeX; i++)
{
for (int j = 0; j < SizeY; j++)
{
if (this[i, j].Test && this[i, j].State != CellState.filled)
{
this[i, j].State = CellState.filled;
if (mode == SolvingMode.hint)
{
return;
}
}
if (!this[i, j].Test && this[i, j].State != CellState.empty)
{
this[i, j].State = CellState.empty;
if (mode == SolvingMode.hint)
{
return;
}
}
}
}
}
/// <summary>
/// Solve for the last unfinished value in checksum
/// </summary>
/// <param name="mode">Solve mode colors the whole puzzle, while hint mode colors only one cell</param>
/// <returns>True if change occured, null if error occured</returns>
private bool?SolveLast(SolvingMode mode)
{
bool change = false;
int position = (int)PutOneFromEnd(_lastUnfinished, _unfinishedRangeEnd);
var lastFilled = LastFilled();
// position now marks where the put end is
// we can now possibly shrink unfinished range
change |= Color(position + _checksum[_lastUnfinished], _unfinishedRangeEnd, CellState.empty, mode);
if (change && mode == SolvingMode.hint)
{
return(true);
}
// unfinished range begins after last colored cell
_unfinishedRangeEnd = position + _checksum[_lastUnfinished] - 1;
//coloring
if (lastFilled - position >= _checksum[_lastUnfinished])
{
// when this happens, error occured (something is wrong with the puzzle)
return(null);
}
if (lastFilled - position >= 0)
{
change |= Color(position, lastFilled, CellState.filled, mode);
if (mode == SolvingMode.hint && change)
{
return(true);
}
// if the whole value is finished, put an empty cell before it, decrease end of an unfinished range and change last unfinished value to the next one
if (lastFilled - position + 1 == _checksum[_lastUnfinished])
{
if (position - 1 > 0 && this[position - 1].State != CellState.empty)
{
this[position - 1].State = CellState.empty;
if (mode == SolvingMode.hint)
{
return(true);
}
}
// position marks the end of first value, position - 1 is an empty space and position - 2 is a new beginning of an unfinished range
_unfinishedRangeEnd = position - 2;
_lastUnfinished--;
}
}
return(change);
}
/// <summary>
/// Solve for the first unfinished value in checksum
/// </summary>
/// <param name="mode">Solve mode colors the whole puzzle, while hint mode colors only one cell</param>
/// <returns></returns>
private bool?SolveFirst(SolvingMode mode)
{
bool change = false;
int position = (int)PutOneFromBeginning(_firstUnfinished, _unfinishedRangeBeginning);
var firstFilled = FirstFilled();
// position now marks where the put end is
// we can now possibly shrink unfinished range
change |= Color(_unfinishedRangeBeginning, position - _checksum[_firstUnfinished], CellState.empty, mode);
if (change && mode == SolvingMode.hint)
{
return(true);
}
// unfinished range begins after last colored cell
_unfinishedRangeBeginning = position - _checksum[_firstUnfinished] + 1;
//coloring
if (position - firstFilled >= _checksum[_firstUnfinished])
{
// when this happens, error occured (something is wrong with the puzzle)
return(null);
}
else if (position - firstFilled >= 0)
{
change |= Color(firstFilled, position, CellState.filled, mode);
if (change && mode == SolvingMode.hint)
{
return(true);
}
// if the whole value is finished, put an empty cell after it, increase beginning of an unfinished range and change first unfinished value to the next one
if (position - firstFilled + 1 == _checksum[_firstUnfinished])
{
if (position + 1 < _size && this[position + 1].State != CellState.empty)
{
this[position + 1].State = CellState.empty;
if (mode == SolvingMode.hint)
{
return(true);
}
change = true;
}
// position marks the end of first value, position + 1 is an empty space and position + 2 is a new beginning of an unfinished range
_unfinishedRangeBeginning = position + 2;
_firstUnfinished++;
}
}
return(change);
}
/// <summary>
/// Solves a single line (row or column) of a puzzle using only one iteration and several methods of solving puzzle
/// </summary>
/// <param name="mode">Solving mode fills all of them, hint mode only fills one</param>
/// <returns>True if a change occured, null if puzzle doesn't have a solution</returns>
public bool?Solve(SolvingMode mode = SolvingMode.solve)
{
if (Check())
{
return(FinishLine(mode));
}
bool?change = false;
if (_firstUnfinished > _lastUnfinished)
{
return(FillWithEmpty(mode));
}
var newChange = SolveRowIntersect(mode);
if (mode == SolvingMode.hint && newChange == true)
{
return(true);
}
if (newChange == null)
{
return(null);
}
change |= newChange;
newChange = SolveFirst(mode);
if (mode == SolvingMode.hint && newChange == true)
{
return(true);
}
if (newChange == null)
{
return(null);
}
change |= newChange;
if (_firstUnfinished >= _checksum.Count)
{
return(change);
}
newChange = SolveLast(mode);
if (mode == SolvingMode.hint && newChange == true)
{
return(true);
}
if (newChange == null)
{
return(null);
}
change |= newChange;
return(change);
}
/// <summary>
/// Set state of cells in a given range to a given state
/// </summary>
/// <param name="start">Beginning of a range to color</param>
/// <param name="finish">End of a range to color</param>
/// <param name="state">State to which cells will be set</param>
/// <param name="mode">Solve mode colors the whole range, while hint mode only colors the first cell</param>
/// <returns>True if something changed</returns>
private bool Color(int start, int finish, CellState state, SolvingMode mode)
{
bool change = false;
for (int i = start; i <= finish; i++)
{
if (this[i].State != state)
{
this[i].State = state;
if (mode == SolvingMode.hint)
{
return(true);
}
change = true;
}
}
return(change);
}
/// <summary>
/// This function is called after the line is properly colored and only fills unknown spaces with empty values
/// </summary>
/// <param name="mode">Solving mode fills all of them, hint mode only fills one</param>
/// <returns>True if change occured</returns>
private bool FinishLine(SolvingMode mode)
{
bool change = false;
for (int i = 0; i < _size; i++)
{
if (this[i].State == CellState.unknown)
{
this[i].State = CellState.empty;
change = true;
if (mode == SolvingMode.hint)
{
return(change);
}
}
}
return(change);
}
/// <summary>
/// Solve the puzzle using state space search
/// </summary>
/// <param name="mode">Solve mode colors the whole puzzle, while hint mode colors only one cell</param>
private bool SolveStateSpace(SolvingMode mode)
{
StateSpaceSearchLine[] lines;
Func <bool> check;
Orientation offsetsOrientation;
// choose to solve in an orientation that has less lines
if (SizeX > SizeY)
{
lines = new StateSpaceSearchLine[SizeY];
offsetsOrientation = Orientation.Horizontal;
check = CheckVerticalTest;
}
else
{
lines = new StateSpaceSearchLine[SizeX];
offsetsOrientation = Orientation.Vertical;
check = CheckHorizontalTest;
}
for (int i = 0; i < SizeY; i++)
{
lines[i] = new StateSpaceSearchLine(this, i, offsetsOrientation);
}
while (true)
{
if (check())
{
break;
}
int lastIncreased = 0;
while (!lines[lastIncreased].IncreaseOffsets())
{
lines[lastIncreased].ResetOffsets();
lastIncreased++;
if (lastIncreased >= SizeX)
{
return(false);
}
}
}
ColorTest(mode);
return(true);
}
/// <summary>
/// Solve the puzzle
/// </summary>
/// <param name="mode">Solve mode colors the whole puzzle, while hint mode colors only one cell</param>
/// <returns>Returns false if the puzzle in its current state doesn't have a solution</returns>
public bool Solve(SolvingMode mode = SolvingMode.solve)
{
bool?change = false;
var lines = new DirectSolveLine[SizeX + SizeY];
for (int i = 0; i < SizeY; i++)
{
lines[i] = new DirectSolveLine(this, Orientation.Horizontal, i);
}
for (int i = SizeY; i < SizeX + SizeY; i++)
{
lines[i] = new DirectSolveLine(this, Orientation.Vertical, i - SizeY);
}
// Iterate through all rows and collumns and solve them as long as change occurs
do
{
change = false;
for (int i = 0; i < SizeX + SizeY; i++)
{
var newChange = lines[i].Solve(mode);
if (mode == SolvingMode.hint && newChange == true)
{
return(true);
}
if (newChange == null)
{
return(false);
}
change |= newChange;
}
} while ((bool)change);
// After the direct solving method fails, solve with state space search
if (!IsSolved())
{
return(SolveStateSpace(mode));
}
return(true);
}
/// <summary>
/// Solves the line using intersection method
/// </summary>
/// <param name="mode">Can be either solveall which solves the whole puzzle, or hint, which only finds a single tile</param>
/// <returns></returns>
private bool?SolveRowIntersect(SolvingMode mode)
{
bool change = false;
var putBeg = PutFromBeginning();
if (putBeg == null)
{
// this means puzzle doesn't have a solution
return(null);
}
var putEnd = PutFromEnd();
if (putEnd == null)
{
return(null);
}
// coloring
for (int i = _firstUnfinished; i <= _lastUnfinished; i++)
{
if (putBeg[i - _firstUnfinished] >= putEnd[i - _firstUnfinished])
{
for (int j = putEnd[i - _firstUnfinished]; j <= putBeg[i - _firstUnfinished]; j++)
{
if (this[j].State != CellState.filled)
{
this[j].State = CellState.filled;
if (mode == SolvingMode.hint)
{
return(true);
}
change = true;
}
}
}
}
return(change);
}
/// <summary>
/// Sets the state of every cell in line to empty
/// </summary>
/// <returns></returns>
private bool?FillWithEmpty(SolvingMode mode = SolvingMode.solve)
{
bool change = false;
for (int i = _unfinishedRangeBeginning; i <= _unfinishedRangeEnd; i++)
{
if (this[i].State == CellState.unknown)
{
this[i].State = CellState.empty;
change = true;
if (mode == SolvingMode.hint)
{
return(change);
}
}
// preasummably empty line shouldn't contain filled cell
if (this[i].State == CellState.filled)
{
return(null);
}
}
return(change);
}
/// <summary>
/// Constructor for testing purpose.
/// </summary>
/// <param name="maxNumberOfAdditionalSantas"></param>
/// <param name="mode"></param>
public GoogleRoutingConfig(int maxNumberOfAdditionalSantas, SolvingMode mode)
{
MaxNumberOfAdditionalSantas = maxNumberOfAdditionalSantas;
Mode = mode;
}
public WrongSolverChoosenException(
SolvingMode typeInUse) :
base(String.Format("{0}{1}{2}",
defaultMessage[0], typeNames[(int)typeInUse], defaultMessage[1]))
{
}