Method PerfectSquare

examples/perfect-square.cpp:198–270

Actual model

  };
  /// Actual model
  PerfectSquare(const SizeOptions& opt)
    : Script(opt),
      x(*this,specs[opt.size()][0],0,specs[opt.size()][1]-1),
      y(*this,specs[opt.size()][0],0,specs[opt.size()][1]-1) {

    const int* s = specs[opt.size()];
    int n = *s++;
    int w = *s++;

    // Restrict position according to square size
    for (int i=0; i<n; i++) {
      rel(*this, x[i], IRT_LQ, w-s[i]);
      rel(*this, y[i], IRT_LQ, w-s[i]);
    }

    IntArgs sa(n,s);

    // Squares do not overlap
    nooverlap(*this, x, sa, y, sa);

    /*
     * Capacity constraints
     *
     */
    switch (opt.propagation()) {
    case PROP_REIFIED:
      {
        for (int cx=0; cx<w; cx++) {
          BoolVarArgs bx(*this,n,0,1);
          for (int i=0; i<n; i++)
            dom(*this, x[i], cx-s[i]+1, cx, bx[i]);
          linear(*this, sa, bx, IRT_EQ, w);
        }
        for (int cy=0; cy<w; cy++) {
          BoolVarArgs by(*this,n,0,1);
          for (int i=0; i<n; i++)
            dom(*this, y[i], cy-s[i]+1, cy, by[i]);
          linear(*this, sa, by, IRT_EQ, w);
        }
      }
      break;
    case PROP_CUMULATIVES:
      {
        IntArgs m(n), dh(n);
        for (int i=0; i<n; i++) {
          m[i]=0; dh[i]=s[i];
        }
        IntArgs limit({w});
        {
          // x-direction
          IntVarArgs e(n);
          for (int i=0; i<n; i++)
            e[i]=expr(*this, x[i]+dh[i]);
          cumulatives(*this, m, x, dh, e, dh, limit, true);
          cumulatives(*this, m, x, dh, e, dh, limit, false);
        }
        {
          // y-direction