/// <summary>
/// Fills the leftInts array with all blocks as far left as possible
/// </summary>
/// <param name="row">row index</param>
/// <param name="leftInts">array to edit</param>
/// <param name="clueIndex">clue to use for this step in recursion</param>
/// <param name="rowPos">current fill position of array. (used for recursion)</param>
/// <returns>false if a contradiction is encountered</returns>
private bool RowLeft(int row, int[] leftInts, int clueIndex, int rowPos)
{
int clue = _ng.GetRowNum(row, clueIndex);
if (clue == 0)
{
for (int i = rowPos; i < leftInts.Length; i++)
{
if (_ng.IsTrue(row, i))
{
return(false);
}
leftInts[i] = clueIndex * 2 - 1;
}
return(true);
}
int localPos = rowPos;
bool posChanged;
while (true)
{
posChanged = false;
for (int i = localPos; i < localPos + clue; i++)
{
if (i >= leftInts.Length)
{
return(false);
}
if (_ng.IsFalse(row, i))
{
for (int j = localPos; j <= i; j++)
{
if (_ng.IsTrue(row, j))
{
return(false);
}
leftInts[j] = clueIndex * 2 - 1;
}
localPos = i + 1;
posChanged = true;
break;
}
leftInts[i] = clueIndex * 2;
}
if (posChanged)
{
continue;
}
if (localPos + clue >= leftInts.Length)
{
return(true);
}
if (!_ng.IsTrue(row, localPos + clue))
{
leftInts[localPos + clue] = clueIndex * 2 + 1;
if (RowLeft(row, leftInts, clueIndex + 1, localPos + clue + 1))
{
return(true);
}
if (_ng.IsTrue(row, localPos))
{
return(false);
}
}
leftInts[localPos] = clueIndex * 2 - 1;
localPos++;
}
}
/// <summary>
/// Checks nonogram for obvious errors related to specified tile.
/// </summary>
/// <param name="row">Row index of tile</param>
/// <param name="column">Column index of tile</param>
/// <returns>True if error was found.</returns>
private bool Error(int row, int column)
{
int lineSum = _ng.RowSum(row);
for (int i = 0; i < _ng.Width; i++)
{
if (_grid[row][i].HasValue && _grid[row][i].Value)
{
lineSum--;
}
if (lineSum < 0)
{
return(true);
}
}
lineSum = _ng.ColumnSum(column);
for (int i = 0; i < _ng.Height; i++)
{
if (_grid[i][column].HasValue && _grid[i][column].Value)
{
lineSum--;
}
if (lineSum < 0)
{
return(true);
}
}
if (_grid[row].All(x => x.HasValue))
{
int num = 0;
List <int> nums = new List <int>();
for (int i = 0; i < _ng.Width; i++)
{
if (_grid[row][i].HasValue && _grid[row][i].Value)
{
num++;
}
else
{
if (num != 0)
{
nums.Add(num);
}
num = 0;
}
}
if (num != 0)
{
nums.Add(num);
}
for (int i = 0; i < nums.Count; i++)
{
if (nums[i] != _ng.GetRowNum(row, i))
{
return(true);
}
}
if (_ng.GetRowNum(row, nums.Count) != 0)
{
return(true);
}
}
if (_grid.All(x => x[column].HasValue))
{
int num = 0;
List <int> nums = new List <int>();
for (int i = 0; i < _ng.Height; i++)
{
if (_grid[i][column].HasValue && _grid[i][column].Value)
{
num++;
}
else
{
if (num != 0)
{
nums.Add(num);
}
num = 0;
}
}
if (num != 0)
{
nums.Add(num);
}
for (int i = 0; i < nums.Count; i++)
{
if (nums[i] != _ng.GetColumnNum(column, i))
{
return(true);
}
}
if (_ng.GetColumnNum(column, nums.Count) != 0)
{
return(true);
}
}
return(false);
}
public void GetRowNumTest()
{
Assert.AreEqual(4, ng.GetRowNum(0, 0));
Assert.AreEqual(0, ng.GetRowNum(0, 1));
Assert.AreEqual(1, ng.GetRowNum(1, 1));
}
