
// some usefull function
template<class T> inline T Min (const T &a,const T &b){return a < b ? a : b;}
template<class T> inline T Max (const T &a,const T & b){return a > b ? a : b;}
template<class T> inline T Abs (const T &a){return a <0 ? -a : a;}
template<class T> inline double Norme (const T &a){return sqrt(a*a);}
template<class T> inline void Exchange (T& a,T& b) {T c=a;a=b;b=c;}
template<class T> inline T Max (const T &a,const T & b,const T & c){return Max(Max(a,b),c);}
template<class T> inline T Min (const T &a,const T & b,const T & c){return Min(Min(a,b),c);}
