#include #define PI 3.14159265358979323846 static inline double atan(double x) { return IEEEDPAtan(x); } double atan2(double y,double x) { return x>=y?(x>=-y? atan(y/x): -PI/2-atan(x/y)): (x>=-y? PI/2-atan(x/y):y>=0? PI +atan(y/x): -PI +atan(y/x)); }