public bool BacktrackingSearch()
{
if (Solved)
{
return(OnSolution());
}
Requirement c = EasiestRequirement;
int s = c.s;
int i = 0;
if (s == 0)
{
return(false);
}
c.Cover();
bool brk = false;
for (Tile r = c.d; r != c; r = r.d)
{
CoverRow(r);
brk = BacktrackingSearch();
UncoverRow();
if (brk)
{
break;
}
}
c.Uncover();
return(brk);
}
public bool BacktrackingProof(TextWriter log)
{
if (Solved)
{
return(OnSolution());
}
Requirement c = EasiestRequirement;
log.WriteLine(c.ToString());
int s = c.s;
int i = 0;
if (s == 0)
{
return(false);
}
c.Cover();
if (s != 1)
{
log.WriteLine("(start of loop)");
}
bool brk = false;
for (Tile r = c.d; r != c; r = r.d)
{
if (s != 1)
{
log.WriteLine("(loop " + (++i) + "/" + s + ")");
}
log.WriteLine(r.Candidate.ToString());
CoverRow(r);
brk = BacktrackingProof(log);
UncoverRow();
if (brk)
{
break;
}
}
c.Uncover();
if (s != 1)
{
log.WriteLine("(end of loop)");
}
return(brk);
}