[C++][NOTE] Floating point maths is not associative.

Be aware of floating point optimizations introduced by constant folding in conformant code Use this:

 
define PI 3.1415
 
double torad2(double n) {
    return 180 / PI * n;
}

Not this:

 
define PI 3.1415
 
double torad1(double n) {
    return n * 180 / PI;
}

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