static private BoxSpot GetCurrentBox(int r, int c)
{
BoxSpot start = new BoxSpot();
if (r < 3)
{
start.r = 0;
}
else if (r < 6)
{
start.r = 3;
}
else if (r < 9)
{
start.r = 6;
}
if (c < 3)
{
start.c = 0;
}
else if (c < 6)
{
start.c = 3;
}
else if (c < 9)
{
start.c = 6;
}
return(start);
}
static private void FindLockedCandidatesCols(string[,] values)
{
for (int n = 1; n < 10; n++)
{
for (int c = 0; c < 9; c++)
{
List <BoxSpot> spots = new List <BoxSpot>();
for (int r = 0; r < 9; r++)
{
if (values[r, c].Contains(n.ToString()))
{
if (spots.Count == 0)
{
spots.Add(new BoxSpot(r, c));
}
else
{
bool same_box = true;
foreach (BoxSpot spot in spots)
{
if (!spot.CompareBox(r, c))
{
same_box = false;
break;
}
}
if (same_box)
{
spots.Add(new BoxSpot(r, c));
}
else
{
spots = null;
break;
}
}
}
}
if (spots != null && spots.Count > 0)
{
BoxSpot box = GetCurrentBox(spots[0].r, spots[0].c);
for (int cc = box.c; cc < box.c + 3; cc++)
{
for (int rr = box.r; rr < box.r + 3; rr++)
{
if (spots.Where(x => x.r == rr && x.c == cc).ToList().Count == 0)
{
values[rr, cc] = values[rr, cc].Replace(n.ToString(), "");
}
}
}
}
}
}
}
static private void FindLockedCandidates(string[,] values)
{
for (int n = 1; n < 10; n++)
{
for (int b_r = 0; b_r < 9; b_r += 3)
{
for (int b_c = 0; b_c < 9; b_c += 3)
{
List <BoxSpot> spots = new List <BoxSpot>();
for (int r = b_r; r < b_r + 3; r++)
{
for (int c = b_c; c < b_c + 3; c++)
{
if (values[r, c].Contains(n.ToString()))
{
BoxSpot spot = new BoxSpot();
spot.r = r;
spot.c = c;
spot.n = n;
spots.Add(spot);
}
}
}
if (spots.Count < 4)
{
int r_count = 0;
int c_count = 0;
for (int i = 1; i < spots.Count; i++)
{
if (spots[i].r == spots[i - 1].r)
{
r_count++;
}
if (spots[i].c == spots[i - 1].c)
{
c_count++;
}
}
if (r_count == spots.Count - 1)
{
for (int c = 0; c < 9; c++)
{
if (spots.Where(s => s.c == c).ToList().Count == 0)
{
values[spots[0].r, c] = values[spots[0].r, c].Replace(spots[0].n.ToString(), "");
}
}
}
if (c_count == spots.Count - 1)
{
for (int r = 0; r < 9; r++)
{
if (spots.Where(s => s.r == r).ToList().Count == 0)
{
values[r, spots[0].c] = values[r, spots[0].c].Replace(spots[0].n.ToString(), "");
}
}
}
}
}
}
}
}