C＋＋编程 从键盘输入8个浮点数，求出其和及平均值。要求编写出求和及求平均值的函数

#include<iostream.h>

double Average(int n,double a[]);
double Sum(int n,double[]);

void main()
{
double array[8];
cout<<"请输入8个浮点数:"<<endl;
for(int i=0;i<8;i++)
cin>>array[i];
cout<<"总和:"<<Sum(8,array)<<endl;
cout<<"平均数:"<<Average(8,array)<<endl;
}

double Sum(int n,double a[])
{
double sum=0.0;
for(int i=0;i<n;i++)
sum+=a[i];
return sum;
}

double Average(int n,double a[])
{
return Sum(n,a)/n;
}

#include <stdio.h>

float sumarray(float *x)
{
float sum=0.0;
for(int i=0;i<8;i++)
{
sum+=*(x+i);
}
return sum;
}

int main()
{
float array[8];
float sum,average;
printf("Enter 8 numbers:\n");
int i;
for( i=0;i<8;i++)