template <typename type>class ddi {		public :		ddi(const double &a, const double &b) : first(a), second(b) {};	ddi(const double &a, const double &b, const type &sq) : first(a), second(b), third(sq) {};	~ddi(){};			friend ostream& operator << (ostream& output, const ddi &p) {				output<<endl<<p.first<<" "<<p.second<<" "<<p.third;		return output; 	};			friend bool operator < (const ddi &a, const ddi &b) {		if (a.first<b.first)		return true;	else if (a.first==b.first && a.second<b.second)		return true;	else		return false;			};		friend bool operator == (const ddi &a, const ddi &b) {		return (a.first==b.first && a.second==b.second);		};		double first;	double second;	type third;			};