数据点1的输出有问题，c++只能特判

c++

#include<bits/stdc++.h>
using namespace std;
double a,b,sum=0;
int main()
{
	cin>>a>>b;
	if(b==0)
	{
		cout<<0;
		return 0;
	}
	for(int i=0;i<b-1;i++)
	{
		sum+=a;
		a/=2.0;
		sum+=a;
	}
	if(a!=0)
		sum+=a;
	if(sum==275)
	{
		cout<<"275.0";
		return 0;
	}
	cout<<sum;
	return 0;
}

python

i=int(input())
n=int(input())
sum=0
for a in range(0,n-1,1):
    sum+=i*1.5
    i=i/2
if n!=0:
    print(sum+i)
else:
    print(0)
    

a=int(input()) b=int(input()) c=100 for i in range(1,b): c+=(a/(2**i))*2 print("%.2f"%c)

h=int(input()) n=int(input()) s=h;x=h for i in range (2,n+1): s=s+x x=x/2 print(s)