public static bool FindCandidateInCol(Grid grid, int row, int col, int Num)
{
for (int i = 0; i < grid.CellsInRow; i++)
{
if (grid.IsCellEmpty(i, col) && i != row && grid.Possibilities(i, col).Contains(Num))
{
return(true);
}
}
return(false);
}
public static bool FindCandidateInBox(Grid grid, int row, int col, int Num)
{
int firstRow = (row / 3) * 3;
int firstCol = (col / 3) * 3;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
if (grid.IsCellEmpty(firstRow + i, firstCol + j) &&
grid.Possibilities(firstRow + i, firstCol + j).Contains(Num) &&
!(firstRow + i != row || firstCol + j != col))
{
return(true);
}
}
}
return(false);
}
/// <summary>
/// Find all Unique Candidates in grid
/// and fill out the uniqueCandidates Array in the grid
/// </summary>
/// <param name="grid">Grid</param>
/// <returns>the number of Unique Candidates</returns>
public static int FindUniqueCandidates(Grid grid)
{
// Grid grid = (Grid)gridOrg.Clone();
grid.resetUniqueCandidates();
nodes = 0;
int uniquesCand = 0;
unsolvableCell = false;
//find Unique Candidates in rows
for (int searchRow = 0; searchRow < grid.CellsInRow; searchRow++)
{
for (int searchCol = 0; searchCol < grid.CellsInRow; searchCol++)
{
if (!grid.IsCellEmpty(searchRow, searchCol))
{
continue;
}
IList candidates = grid.Possibilities(searchRow, searchCol);
IList candidates2 = new ArrayList(candidates);
if (candidates.Count > 1)
{
for (int cand = 0; cand < candidates.Count; cand++)
{
if (FindCandidateInRow(grid, searchRow, searchCol, (int)candidates[cand]))
{
candidates2.Remove(candidates[cand]);
}
}
}
if (candidates2.Count == 1)
{
grid.uniqueCandidates[searchRow, searchCol] = (int)candidates2[0];
}
}
}
//find Unique Candidates in colums
for (int searchCol = 0; searchCol < grid.CellsInRow; searchCol++)
{
for (int searchRow = 0; searchRow < grid.CellsInRow; searchRow++)
{
if (!grid.IsCellEmpty(searchRow, searchCol))
{
continue;
}
IList candidates = grid.Possibilities(searchRow, searchCol);
IList candidates2 = new ArrayList(candidates);
if (candidates.Count > 1)
{
for (int cand = 0; cand < candidates.Count; cand++)
{
if (FindCandidateInCol(grid, searchRow, searchCol, (int)candidates[cand]))
{
candidates2.Remove(candidates[cand]);
}
}
}
if (candidates2.Count == 1)
{
grid.uniqueCandidates[searchRow, searchCol] = (int)candidates2[0];
}
}
}
//find Unique Candidates in boxes
for (int searchRow = 0; searchRow < grid.CellsInRow; searchRow++)
{
for (int searchCol = 0; searchCol < grid.CellsInRow; searchCol++)
{
if (!grid.IsCellEmpty(searchRow, searchCol))
{
continue;
}
IList candidates = grid.Possibilities(searchRow, searchCol);
IList candidates2 = new ArrayList(candidates);
if (candidates.Count > 1)
{
for (int cand = 0; cand < candidates.Count; cand++)
{
if (FindCandidateInBox(grid, searchRow, searchCol, (int)candidates[cand]))
{
candidates2.Remove(candidates[cand]);
}
}
}
else
{
if (candidates.Count == 1)
{
uniquesCand++;
}
else
{
unsolvableCell = true;
}
}
if (candidates2.Count == 1)
{
grid.uniqueCandidates[searchRow, searchCol] = (int)candidates2[0];
}
}
}
for (int i = 0; i < 9; i++)
{
for (int j = 0; j < 9; j++)
{
if (grid.uniqueCandidates[i, j] != 0)
{
nodes++;
}
}
}
nodes = nodes + (uniquesCand / 2);
return(nodes);
}
public static bool FindCandidateInBox(Grid grid, int row, int col, int Num)
{
int firstRow = (row / 3) * 3;
int firstCol = (col / 3) * 3;
for (int i = 0; i < 3; i++)
{
for (int j = 0; j < 3; j++)
{
if (grid.IsCellEmpty(firstRow + i, firstCol + j) &&
grid.Possibilities(firstRow + i, firstCol + j).Contains(Num) &&
!(firstRow + i != row || firstCol + j != col))
{
return true;
}
}
}
return false;
}
public static bool FindCandidateInCol(Grid grid, int row, int col, int Num)
{
for (int i = 0; i < grid.CellsInRow; i++)
{
if (grid.IsCellEmpty(i, col) && i != row && grid.Possibilities(i, col).Contains(Num))
{
return true;
}
}
return false;
}
/// <summary>
/// Find all Unique Candidates in grid
/// and fill out the uniqueCandidates Array in the grid
/// </summary>
/// <param name="grid">Grid</param>
/// <returns>the number of Unique Candidates</returns>
public static int FindUniqueCandidates(Grid grid)
{
// Grid grid = (Grid)gridOrg.Clone();
grid.resetUniqueCandidates();
nodes = 0;
int uniquesCand = 0;
unsolvableCell = false;
//find Unique Candidates in rows
for (int searchRow = 0; searchRow < grid.CellsInRow; searchRow++)
{
for (int searchCol = 0; searchCol < grid.CellsInRow; searchCol++)
{
if (!grid.IsCellEmpty(searchRow, searchCol))
{
continue;
}
IList candidates = grid.Possibilities(searchRow, searchCol);
IList candidates2 = new ArrayList(candidates);
if (candidates.Count > 1)
{
for (int cand = 0; cand < candidates.Count; cand++)
{
if (FindCandidateInRow(grid, searchRow, searchCol, (int)candidates[cand]))
{
candidates2.Remove(candidates[cand]);
}
}
}
if (candidates2.Count == 1)
{
grid.uniqueCandidates[searchRow, searchCol] = (int)candidates2[0];
}
}
}
//find Unique Candidates in colums
for (int searchCol = 0; searchCol < grid.CellsInRow; searchCol++)
{
for (int searchRow = 0; searchRow < grid.CellsInRow; searchRow++)
{
if (!grid.IsCellEmpty(searchRow, searchCol))
{
continue;
}
IList candidates = grid.Possibilities(searchRow, searchCol);
IList candidates2 = new ArrayList(candidates);
if (candidates.Count > 1)
{
for (int cand = 0; cand < candidates.Count; cand++)
{
if (FindCandidateInCol(grid, searchRow, searchCol, (int)candidates[cand]))
{
candidates2.Remove(candidates[cand]);
}
}
}
if (candidates2.Count == 1)
{
grid.uniqueCandidates[searchRow, searchCol] = (int)candidates2[0];
}
}
}
//find Unique Candidates in boxes
for (int searchRow = 0; searchRow < grid.CellsInRow; searchRow++)
{
for (int searchCol = 0; searchCol < grid.CellsInRow; searchCol++)
{
if (!grid.IsCellEmpty(searchRow, searchCol))
{
continue;
}
IList candidates = grid.Possibilities(searchRow, searchCol);
IList candidates2 = new ArrayList(candidates);
if (candidates.Count > 1)
{
for (int cand = 0; cand < candidates.Count; cand++)
{
if (FindCandidateInBox(grid, searchRow, searchCol, (int)candidates[cand]))
{
candidates2.Remove(candidates[cand]);
}
}
}
else
{
if (candidates.Count == 1)
{
uniquesCand++;
}
else
{
unsolvableCell = true;
}
}
if (candidates2.Count == 1)
{
grid.uniqueCandidates[searchRow, searchCol] = (int)candidates2[0];
}
}
}
for (int i = 0; i < 9; i++)
{
for (int j = 0; j < 9; j++)
{
if (grid.uniqueCandidates[i, j] != 0)
{
nodes++;
}
}
}
nodes = nodes + (uniquesCand / 2);
return nodes;
}