为什么本题这个代码就过一个点

#include<bits/stdc++.h>
using namespace std;
int main()
{
	unsigned long long t,x,y,flag;
	cin>>t;
	while(t--)
	{
		cin>>x>>y;
		if(x>y)
			swap(x,y);
		cout<<"1 "<<(x*y/__gcd(x,y))*1.0/__gcd(x,y)<<endl;
	}
} 

然后这样AC

#include<bits/stdc++.h>
using namespace std;
int main()
{
	unsigned long long t,x,y,flag;
	cin>>t;
	while(t--)
	{
		cin>>x>>y;
		if(x>y)
			swap(x,y);
		cout<<"1 "<<(x*y/__gcd(x,y))/__gcd(x,y)<<endl;
	}
}