据题意，用for逆推就好了。 ````#include<bits/stdc++.h> using namespace std; int main(){ int n; double height,hh; cin>>n; height=hh=n; for(int i=2;i<=10;i++){ hh/=2; height+=hh*2; } cout<<height<<endl<<hh/2<<endl; return 0; }`

#include<bits/stdc++.h>
using namespace std;
int main()
{
	double a;
    double b=0;
	cin >> a;
	for(int i=1;i<=19;i++)
	{
		b+=a;
        if(i%2==1)a/=2;
	}
	cout << b;
    cout << endl;
    cout << a;
}