void Sudoku_SetCell( struct Sudoku* sud, unsigned int x, unsigned int y, unsigned int value ) {
unsigned int i, j;
if( value == 0 ) return;
//store value in grid
sud->cellvalue[y][x] = value;
//reduce value to shiftvalue (1ll << 0) == 1
value--;
//set all other values to impossible
sud->grid[y][x] = 0ll;
//store value in contains
sud->contains[CONTAINS_COL][x] |= ( 1ll << value );
sud->contains[CONTAINS_ROW][y] |= ( 1ll << value );
sud->contains[CONTAINS_BOX][BOXINDEX( sud, x, y )] |= ( 1ll << value );
//remove other cells possibility for value
//col / row
for( i = 0; i < sud->length; i++ ) {
sud->grid[y][i] &= ~( 1ll << value );
sud->grid[i][x] &= ~( 1ll << value );
}
//box
//determine box start indices
x -= ( x % sud->length_of_box );
y -= ( y % sud->length_of_box );
//invalidate possibility
for( j = y; j < y + sud->length_of_box; j++ ) {
for( i = x; i < x + sud->length_of_box; i++ ) {
sud->grid[j][i] &= ~( 1ll << value );
}
}
}
int strategy15( struct Sudoku* sud, unsigned int x, unsigned int y ) {
struct Combinator c;
unsigned int cellok[64];
unsigned int subset[64];
unsigned int buffer[64];
unsigned int changed;
unsigned int i, j, k;
unsigned int index[64] = { 0 };
unsigned int combination[5] = { 0 };
unsigned int curcell = BOXINDEX( sud, x, y );
j = 0;
//count number of empty cells in neighbourhood
for( i = 0; i < sud->length; i++ ) {
if( sud->cellboxvalue[y][x][i] == 0 && i != curcell ) {
index[j++] = i;
}
}
if( j <= SUDOKU_SUBSET_MIN ) return 0;
//for defined subset sizes
for( i = SUDOKU_SUBSET_MIN; i <= SUDOKU_SUBSET_MAX; i++ ) {
Combinator_Initialize( &c, i, index, j );
combination[i] = curcell;
//for each available combination
while( Combinator_GetNext( &c, combination ) == 0 ) {
vinitl( subset, 0 );
for( j = 0; j <= i; j++ ) {
for( k = j + 1; k <= i; k++ ) {
//combine all subsets
//create validation mask
vandl( *sud->cellbox[y][x][combination[j]], *sud->cellbox[y][x][combination[k]], buffer );
if( vpopcntl( buffer ) != 0 ) {
cellok[j] = 1;
cellok[k] = 1;
vsetl( subset, buffer );
break;
}
}
}
//validate subset
if( vpopcntl( cellok ) != i + 1 ) continue;
for( j = 0; j < sud->length; j++ ) {
if( cellok[j] == 0 ) vunsetl( subset, *sud->cellbox[y][x][j] );
}
if( vpopcntl( subset ) != i + 1 ) continue;
//remove other candidates from cells in subset
changed = 0;
for( j = 0; j < sud->length; j++ ) {
if( subset[j] != 0 ) {
vnotl( subset, buffer );
vandl( buffer, sud->cellboxvalue[y][x][j], buffer );
changed += vpopcntl( buffer );
vandl( sud->cellboxvalue[y][x][j], subset, sud->cellboxvalue[y][x][j] );
}
}
return changed != 0;
}
}
return 0;
}
//:/
int rule15( struct Sudoku* sud, unsigned int x, unsigned int y ) {
struct Combinator c;
SudokuCell cellok;
SudokuCell subset;
SudokuCell changed;
unsigned int i, j, k;
unsigned int index[64] = { 0 };
unsigned int combination[5] = { 0 };
unsigned int curcell = BOXINDEX( sud, x, y );
j = 0;
for( i = 0; i < sud->length; i++ ) {
if( *sud->cellboxvalue[y][x][i] == 0 && i != curcell ) {
index[j++] = i;
}
}
if( j <= 3 ) return 0;
for( i = 2; i < 4; i++ ) {
Combinator_Initialize( &c, i, index, j );
combination[i] = curcell;
while( Combinator_GetNext( &c, combination ) == 0 ) {
subset = 0ll;
for( j = 0; j <= i; j++ ) {
for( k = j + 1; k <= i; k++ ) {
if( *sud->cellbox[y][x][combination[j]] & *sud->cellbox[y][x][combination[k]] ) {
cellok |= ( ( 1 << j ) | ( 1 << k ) );
subset |= *sud->cellbox[y][x][combination[j]] & *sud->cellbox[y][x][combination[k]];
break;
}
}
}
if( __popcnt64( cellok ) != i + 1 ) continue;
for( j = 0; j < sud->length; j++ ) {
if( ( cellok & ( 1ll << j ) ) == 0 ) subset &= ( ~( *sud->cellbox[y][x][j] ) );
}
if( __popcnt64( subset ) != i + 1 ) continue;
changed = 0;
for( j = 0; j < sud->length; j++ ) {
if( ( subset & ( 1ll << j ) ) != 0 ) {
changed |= ( *sud->cellbox[y][x][j] & ( ~( subset ) ) );
*sud->cellbox[y][x][j] &= subset;
}
}
return changed != 0;
}
}
return 0;
}
int strategy15( struct Sudoku* sud, unsigned int x, unsigned int y ) {
struct Combinator c;
SudokuCell cellok;
SudokuCell subset;
SudokuCell changed;
unsigned int i, j, k;
unsigned int index[64] = { 0 };
unsigned int combination[5] = { 0 };
unsigned int curcell = BOXINDEX( sud, x, y );
j = 0;
//count number of empty cells in neighbourhood
for( i = 0; i < sud->length; i++ ) {
if( *sud->cellboxvalue[y][x][i] == 0 && i != curcell ) {
index[j++] = i;
}
}
if( j <= SUDOKU_SUBSET_MIN ) return 0;
//for defined subset sizes
for( i = SUDOKU_SUBSET_MIN; i <= SUDOKU_SUBSET_MAX; i++ ) {
Combinator_Initialize( &c, i, index, j );
combination[i] = curcell;
//for each available combination
while( Combinator_GetNext( &c, combination ) == 0 ) {
subset = 0ll;
for( j = 0; j <= i; j++ ) {
for( k = j + 1; k <= i; k++ ) {
//combine all subsets
//create validation mask
if( *sud->cellbox[y][x][combination[j]] & *sud->cellbox[y][x][combination[k]] ) {
cellok |= ( ( 1 << j ) | ( 1 << k ) );
subset |= *sud->cellbox[y][x][combination[j]] & *sud->cellbox[y][x][combination[k]];
break;
}
}
}
//validate subset
if( __popcnt64( cellok ) != i + 1 ) continue;
for( j = 0; j < sud->length; j++ ) {
if( ( cellok & ( 1ll << j ) ) == 0 ) subset &= ( ~( *sud->cellbox[y][x][j] ) );
}
if( __popcnt64( subset ) != i + 1 ) continue;
//remove other candidates from cells in subset
changed = 0;
for( j = 0; j < sud->length; j++ ) {
if( ( subset & ( 1ll << j ) ) != 0 ) {
changed |= ( *sud->cellbox[y][x][j] & ( ~( subset ) ) );
*sud->cellbox[y][x][j] &= subset;
}
}
return changed != 0;
}
}
return 0;
}