Method Partition

examples/partition.cpp:53–93

Actual model

public:
  /// Actual model
  Partition(const SizeOptions& opt)
    : Script(opt),
      x(*this,opt.size(),1,2*opt.size()),
      y(*this,opt.size(),1,2*opt.size()) {
    const int n = opt.size();

    // Break symmetries by ordering numbers in each group
    rel(*this, x, IRT_LE);
    rel(*this, y, IRT_LE);

    rel(*this, x[0], IRT_LE, y[0]);

    IntVarArgs xy(2*n);
    for (int i = n; i--; ) {
      xy[i] = x[i]; xy[n+i] = y[i];
    }
    distinct(*this, xy, opt.ipl());

    IntArgs c(2*n);
    for (int i = n; i--; ) {
      c[i] = 1; c[n+i] = -1;
    }
    linear(*this, c, xy, IRT_EQ, 0);

    // Array of products
    IntVarArgs sxy(2*n), sx(n), sy(n);

    for (int i = n; i--; ) {
      sx[i] = sxy[i] =   expr(*this, sqr(x[i]));
      sy[i] = sxy[n+i] = expr(*this, sqr(y[i]));
    }
    linear(*this, c, sxy, IRT_EQ, 0);

    // Redundant constraints
    linear(*this, x, IRT_EQ, 2*n*(2*n+1)/4);
    linear(*this, y, IRT_EQ, 2*n*(2*n+1)/4);
    linear(*this, sx, IRT_EQ, 2*n*(2*n+1)*(4*n+1)/12);
    linear(*this, sy, IRT_EQ, 2*n*(2*n+1)*(4*n+1)/12);

    branch(*this, xy, INT_VAR_AFC_SIZE_MAX(opt.decay()), INT_VAL_MIN());
  }

  /// Constructor used during cloning \a s
  Partition(Partition& s) : Script(s) {