Method SudokuSet

examples/sudoku-advanced.cpp:246–316

Constructor

public:
  /// Constructor
  SudokuSet(const SizeOptions& opt)
    : Sudoku(opt),
      y(*this,n*n,IntSet::empty,1,n*n*n*n,
        static_cast<unsigned int>(n*n),static_cast<unsigned int>(n*n)) {

    const int nn = n*n;

    Region r;
    IntSet* row = r.alloc<IntSet>(nn);
    IntSet* col = r.alloc<IntSet>(nn);
    IntSet* block = r.alloc<IntSet>(nn);

    // Set up the row and column set constants
    int* dsc = r.alloc<int>(nn);
    for (int i=0; i<nn; i++) {
      row[i] = IntSet((i*nn)+1, (i+1)*nn);

      for (int j=0; j<nn; j++) {
        dsc[j] = (j*nn)+1+i;
      }
      col[i] = IntSet(dsc, nn);
    }

    // Set up the block set constants
    int* dsb_arr = r.alloc<int>(nn);
    for (int i=0; i<n; i++) {
      for (int j=0; j<n; j++) {

        for (int ii=0; ii<n; ii++) {
          for (int jj=0; jj<n; jj++) {
            dsb_arr[ii*n+jj] = j*nn*n+i*n+jj*nn+ii+1;
          }
        }
        block[i*n+j] = IntSet(dsb_arr, nn);
      }
    }

    IntSet full(1, nn*nn);
    // All x must be pairwise disjoint and partition the field indices
    rel(*this, SOT_DUNION, y, SetVar(*this, full, full));

    // The x must intersect in exactly one element with each
    // row, column, and block
    for (int i=0; i<nn; i++)
      for (int j=0; j<nn; j++) {
        SetVar inter_row(*this, IntSet::empty, full, 1U, 1U);
        rel(*this, y[i], SOT_INTER, row[j], SRT_EQ, inter_row);
        SetVar inter_col(*this, IntSet::empty, full, 1U, 1U);
        rel(*this, y[i], SOT_INTER, col[j], SRT_EQ, inter_col);
        SetVar inter_block(*this, IntSet::empty, full, 1U, 1U);
        rel(*this, y[i], SOT_INTER, block[j], SRT_EQ, inter_block);
      }

    // Fill-in predefined fields
    for (int i=0; i<nn; i++)
      for (int j=0; j<nn; j++)
        if (int idx = sudokuField(examples[opt.size()], nn, i, j))
          dom(*this, y[idx-1], SRT_SUP, (i+1)+(j*nn) );