Problem 2: GCD

[ghost]

The greatest common divisor is a common number theory operation.

Here's a few implementations to give you some ideas:

int gcd(int a,int b){while(b)b^=a^=b^=a%=b;return a;}
int gcd(int a,int b){while(a&&b)a>b?a%=b:b%=a;return a+b;}

[ghost]

https://github.com/Ta180m/Idiot-Code-Golf/blob/main/gcd/gcd.cpp

Euclidean algorithm except modulos are computed using trig functions!