Method getAlternative

gecode/gist/spacenode.hpp:168–178

  }

  forceinline int
  SpaceNode::getAlternative(const NodeAllocator& na) const {
    SpaceNode* p = getParent(na);
    if (p == nullptr)
      return -1;
    for (int i=static_cast<int>(p->getNumberOfChildren()); i--;)
      if (p->getChild(na,i) == this)
        return i;
    GECODE_NEVER;
    return -1;
  }

  forceinline const Choice*
  SpaceNode::getChoice(void) {