递归求最大公约数

#include "iostream"#include "cmath"using namespace std;//一个数和0的最大公约数就是这个数本身//a / b = q + r => gcd(a,b) = gcd(b,r)int gcd(int a, int b){int r = a % b; //余数int q = a / b; //商''''''if (r == 0)return b;elsereturn gcd(b,r);}int main(){cout << gcd(4,18);return 0;}