Can someone explain why we compare b to zero then swap it as a in the argument? What is the reason behind this approach? I am having a hard time understanding this algorithm.

public int gcd(int a, int b) {
   if (b==0) return a;
   return gcd(b,a%b);
}

CodePudding user response：

From what I understand, it is a principle called Euclidean algorithm. Two values do not change if the larger is replaced by its difference with the smaller value. GCD is the largest positive value that divides two or more values without leaving a remainder.