C++ rational类代码示例

 void assign(contains_app & x,expr * fml,const rational & v) {
     SASSERT(v.is_unsigned());
     eq_atoms& eqs = get_eqs(x.x(), fml);            
     unsigned uv = v.get_unsigned();
     uint64 domain_size;
     if (is_small_domain(x, eqs, domain_size)) {
         SASSERT(v < rational(domain_size, rational::ui64()));
         assign_small_domain(x, eqs, uv);
     }
     else {
         assign_large_domain(x, eqs, uv);
     }
 }

 bool is_target_core(expr * n, rational & u) {
     if (!is_uninterp_const(n))
         return false;
     rational l; bool s;
     if (m_bm.has_lower(n, l, s) &&
         m_bm.has_upper(n, u, s) &&  
         l.is_zero() &&
         !u.is_neg() && 
         u.get_num_bits() <= m_max_bits) {
         
         return true;
     }
     return false;
 }

 void subst(contains_app & x,const rational & v,expr_ref & fml, expr_ref* def) {
     SASSERT(v.is_unsigned());
     eq_atoms& eqs = get_eqs(x.x(), fml);           
     unsigned uv = v.get_unsigned();
     uint64 domain_size;
     if (is_small_domain(x, eqs, domain_size)) {
         SASSERT(uv < domain_size);
         subst_small_domain(x, eqs, uv, fml);
     }
     else {
         subst_large_domain(x, eqs, uv, fml);
     }
     if (def) {
         *def = 0; // TBD
     }
 }

 bool is_target(expr * var, rational & val) {
     bool strict;
     return 
         is_uninterp_const(var) && 
         (!m_normalize_int_only || m_util.is_int(var)) && 
         m_bm.has_lower(var, val, strict) && 
         !val.is_zero();
 }

// **** 1.Add a square root function to the rational class. ****
rational squareRoot(const rational &r)
{
	assert(r.numerator()>0);

	double top = r.numerator();
	double bot = r.denominator();

	double topSqrt = sqrt(top);
	double botSqrt = sqrt(bot);

	// Estimate if not a perfect square
	if ((fmod(topSqrt,1)!=0) ||(fmod(botSqrt,1)!=0))
	{
		topSqrt = sqrt(100*top);
		botSqrt = sqrt(100*bot);
	}
	return rational((int)topSqrt, (int)botSqrt);
}

bool static_features::is_diff_term(expr const * e, rational & r) const {
    // lhs can be 'x' or '(+ k x)'
    if (!is_arith_expr(e)) {
        r.reset();
        return true;
    }
    if (is_numeral(e, r))
        return true;
    return m_autil.is_add(e) && to_app(e)->get_num_args() == 2 && is_numeral(to_app(e)->get_arg(0), r) && !is_arith_expr(to_app(e)->get_arg(1));
}

void print(rational a){
	if(a.get_chisl()==0)std::cout<<"\n 0 ";else{
		if(a.get_chisl()==a.get_znam())std::cout<<"\n 1";else{
			if(a.get_znam()==1)std::cout<<"\n "<<a.get_chisl();else{
 			 std::cout<<"\n "<<a.get_chisl()<<"/"<<a.get_znam();
			}
		}
	}
}

 unsigned context::scoped_state::add(expr* f, rational const& w, symbol const& id) {
     if (w.is_neg()) {
         throw default_exception("Negative weight supplied. Weight should be positive");
     }
     if (w.is_zero()) {
         throw default_exception("Zero weight supplied. Weight should be positive");
     }
     if (!m.is_bool(f)) {
         throw default_exception("Soft constraint should be Boolean");
     }
     if (!m_indices.contains(id)) {
         m_objectives.push_back(objective(m, id));
         m_indices.insert(id, m_objectives.size() - 1);
     }
     SASSERT(m_indices.contains(id));        
     unsigned idx = m_indices[id];
     m_objectives[idx].m_terms.push_back(f);
     m_objectives[idx].m_weights.push_back(w);
     m_objectives_term_trail.push_back(idx);
     return idx;
 }

rational operator - (const rational &left, const rational &right)
{
  rational result(
		  left.numerator() * right.denominator() -
		  right.numerator() * left.denominator(),
		  left.denominator() * right.denominator());
  return result;
}

int main()
{
   int shift = 20;
   hashset hset;
   hashset::iterator iter;
   i64 mup = (1LL<<(2*shift))-1;
   i64 mdown = (1LL<<shift)-1;
   mup -= mdown;
   vector<rational> vr; 
   for(int di = 2; di <= 35; ++di)
       for(int ni = 1; ni < di; ++ni){
            int common = gcd(ni, di);
            if(common> 1) continue;
            vr.push_back(rational(ni, di));
       }
   sort(vr.begin(), vr.end());

    for(unsigned int i = 0; i < vr.size(); ++i){
        for(unsigned int j = i; j < vr.size(); ++j){
            rational& r1 = vr[i];
            rational& r2 = vr[j];
            const rational xr = r1 + r2;
            //x+y=z
            if(xr.pnum() >= xr.pden()) break;
            if(xr.pden() <= 35){
                rational xr2 = xr + xr;
                i64 value = (xr2.pden()<<shift)+(xr2.pnum());
                assert(((value & mup)>>shift) == xr2.pden());
                assert((value & mdown) == xr2.pnum());
                iter = hset.find(value);
                if(iter == hset.end()){
                    hset.insert(value);
                    //printf("a %lld %lld %lld %lld %lld %lld %lld %lld\n", r1.pnum(), r1.pden(), 
                    //    r2.pnum(), r2.pden(), xr.pnum(), xr.pden(), xr2.pnum(), xr2.pden());
                }
            }
        }
    }

sym pow(const sym &s,const rational &q) {

	if(typeid(*s.expr)==typeid(sym::sym_num)) 
		return sym(pow(((sym::sym_num *)s.expr)->value,q.eval()));

	sym snew;
	
	snew.context=s.check_context();
	delete snew.expr;
	snew.expr=s.expr->clone();
	snew.expr=snew.expr->pow(q)->reduce();

	return snew;
}

 BOOST_CONSTEXPR explicit
    rational(rational<NewType> const &r)
    : num(r.numerator()), den(is_normalized(int_type(r.numerator()),
    int_type(r.denominator())) ? r.denominator() :
    (BOOST_THROW_EXCEPTION(bad_rational("bad rational: denormalized conversion")), 0)){}

	bool operator==(const rational<T2> &f) const
	{
		return ((this->_numerator == f.numerator()) &&
		        (this->_denominator == f.denominator()));
	}

sym::sym(const rational &q) {
	context=NULL;
	expr=new sym::sym_num(q.eval());
}

rational rational::operator /(const rational& second) const {
    return rational(getNum() * second.getDenom(), getDenom() * second.getNum());
}