辗转相除
#include <iostream>
using namespace std;
int main()
{
int A,B,t,i;
cin>>A>>B;
if(A>B){t=A;A=B;B=t;}
for(i=A;i>=1;i--)
if(A%i==0&&B%i==0) break;
cout<<i;
}
2、
#include <iostream>
using namespace std;
int main()
{
int A,B,yu,x,y,i,t;
cin>>A>>B;
if(A>B){t=A;A=B;B=t;}
x=A;y=B;
yu=y%x;
while(yu!=0)
{
y=x;x=yu;
yu=y%x;
}
cout<<x<<endl;
cout<<A*B/x;
}