Clause*
QueryInterface::computeClauseFromCandidates()
{
Clause* clause = new Clause();
unsigned int j = 0;
for( unsigned int i = 0; i < candidates.size(); i++ )
{
Var v = candidates[ j ] = candidates[ i ];
assert( !solver.isUndefined( v ) );
if( !solver.isTrue( v ) )
continue;
if( solver.getDecisionLevel( v ) == 0 )
addAnswer( v );
else
{
clause->addLiteral( Literal( v, NEGATIVE ) );
j++;
}
}
candidates.shrink( j );
clause->setCanBeDeleted( false );
printCandidates();
return clause;
}
void checkTriplesInCol(sudoku* s, int col){
int y1, y2, y3;
for (y1=0; y1<9; ++y1){
for (y2=y1+1; y2<9; ++y2){
for (y3=y2+1; y3<9; ++y3){
// combine three cells
int i1 = getIndex(col, y1);
int i2 = getIndex(col, y2);
int i3 = getIndex(col, y3);
int combi = (s->candidates[i1] | s->candidates[i2] | s->candidates[i3]) & ~1;
printf ("Testing col %d: %d, %d, %d => %d, %d, %d => %d\n", col, y1, y2, y3, s->candidates[i1], s->candidates[i2], s->candidates[i3], combi);
if (countBits(combi)==3){
// "backup fields"
int b1, b2, b3;
b1 = s->candidates[i1];
b2 = s->candidates[i2];
b3 = s->candidates[i3];
int i;
for (i=1; i<=9; ++i){
if (isCandidate(i, combi) && s->fields[i1]!=0 && s->fields[i2]!=0 && s->fields[i3]!=0){
printf ("Found a triple in col %d: %d, %d, %d => %d\n", col, y1, y2, y3, combi);
removeCandidatesInCol(s, y1, col, i);
}
}
s->candidates[i1] = b1;
s->candidates[i2] = b2;
s->candidates[i3] = b3;
printCandidates(s);
}
}
}
}
}
void checkTriplesInRow(sudoku* s, int row){
int x1, x2, x3;
for (x1=0; x1<9; ++x1){
for (x2=x1+1; x2<9; ++x2){
for (x3=x2+1; x3<9; ++x3){
// combine three cells
int i1 = getIndex(x1, row);
int i2 = getIndex(x2, row);
int i3 = getIndex(x3, row);
int combi = (s->candidates[i1] | s->candidates[i2] | s->candidates[i3]) & ~1;
printf ("Testing row %d: %d, %d, %d => %d, %d, %d => %d\n", row, x1, x2, x3, s->candidates[i1], s->candidates[i2], s->candidates[i3], combi);
if (countBits(combi)==3){
// "backup fields"
int b1, b2, b3;
b1 = s->candidates[i1];
b2 = s->candidates[i2];
b3 = s->candidates[i3];
int i;
for (i=1; i<=9; ++i){
if (isCandidate(i, combi) && s->fields[i1]!=0 && s->fields[i2]!=0 && s->fields[i3]!=0){
printf ("Found a triple in row %d: %d, %d, %d => %d\n", row, x1, x2, x3, combi);
removeCandidatesInRow(s, row, x1, i);
}
}
s->candidates[i1] = b1;
s->candidates[i2] = b2;
s->candidates[i3] = b3;
printCandidates(s);
}
}
}
}
}
void checkPairsInRow(sudoku* s, int row){
int x1, x2;
for (x1=0; x1<9; ++x1){
for (x2=x1+1; x2<9; ++x2){
// combine two cells
int i1 = getIndex(x1, row);
int i2 = getIndex(x2, row);
int combi = (s->candidates[i1] | s->candidates[i2]) & ~1;
printf ("Testing row %d: %d, %d, => %d, %d => %d\n", row, x1, x2, s->candidates[i1], s->candidates[i2], combi);
if (countBits(combi)==2 && s->fields[i1]==0 && s->fields[i2]==0){
// "backup fields"
int b1, b2;
b1 = s->candidates[i1];
b2 = s->candidates[i2];
int i;
for (i=1; i<=9; ++i){
if (isCandidate(i, combi) && s->fields[i1]!=0 && s->fields[i2]!=0){
printf ("Found a pair in row %d: %d, %d, => %d\n", row, x1, x2, combi);
removeCandidatesInRow(s, row, x1, i);
}
}
s->candidates[i1] = b1;
s->candidates[i2] = b2;
printCandidates(s);
}
}
}
}
int solve(sudoku* s){
fixGivens(s);
if (fixSingletons(s)) printf("Singletons found.\n");
if (fixPairs(s)) printf("Pairs found.\n");
if (fixTriples(s)) printf("Triples found.\n");
printCandidates(s);
backtrack(s);
}
void
QueryInterface::reduceCandidates()
{
unsigned int j = 0;
for( unsigned int i = 0; i < candidates.size(); i++ )
{
Var v = candidates[ j ] = candidates[ i ];
assert( !solver.isUndefined( v ) );
if( !solver.isTrue( v ) )
continue;
if( solver.getDecisionLevel( v ) == 0 )
addAnswer( v );
else
j++;
}
candidates.shrink( j );
printCandidates();
}
int fixPairs(sudoku* s){
int* indices;
int pair;
int i;
int row, col;
int findings=0;
// pairs in rows?
for(row=0; row<9; ++row){
for (i=0; i<36; ++i){
indices=pairIndices[i];
if ((s->fields2d[row][indices[0]]==0) &&
(s->fields2d[row][indices[1]]==0)){ // TODO: why does this segfault?
pair=(s->candidates2d[row][indices[0]] | s->candidates2d[row][indices[1]]);
debugprintf("Row %d, cols %d and %d (%u, %u) have %d candidates in sum:\n",
row, indices[0], indices[1],
s->candidates2d[row][indices[0]],
s->candidates2d[row][indices[1]], countBits(pair));
int j;
for (j=1; j<10; ++j){
if ((1u<<j)&pair){
debugprintf("%d, ", j);
}
}
debugprintf("\n");
if (countBits(pair)==2){
debugprintf("Fixing pair in row %d (cols %d, %d)\n", row, indices[0], indices[1]);
findings += fixPairInRow(s, row, indices[0], indices[1]);
#if DEBUG==1
printCandidates(s);
#endif
}
}
}
}
// pairs in columns?
for(col=0; col<9; ++col){
for (i=0; i<36; ++i){
indices=pairIndices[i];
if ((s->fields2d[indices[0]][col]==0) &&
(s->fields2d[indices[1]][col]==0)){ // TODO: why does this segfault?
pair=(s->candidates2d[indices[0]][col] | s->candidates2d[indices[1]][col]);
debugprintf("Col %d, rows %d and %d (%u, %u) have %d candidates in sum:\n",
col, indices[0], indices[1],
s->candidates2d[indices[0]][col],
s->candidates2d[indices[1]][col], countBits(pair));
int j;
for (j=1; j<10; ++j){
if ((1u<<j)&pair){
debugprintf("%d, ", j);
}
}
debugprintf("\n");
if (countBits(pair)==2){
debugprintf("Fixing pair in col %d (rows %d, %d)\n", col, indices[0], indices[1]);
findings += fixPairInCol(s, col, indices[0], indices[1]);
#if DEBUG==1
printCandidates(s);
#endif
}
}
}
}
// do we need additional rounds?
if (findings){
fixPairs(s);
return 1;
}
return 0;
}