c++ I/O流相关，求纠错

Question

1. 编写一段程序，从键盘任意输入十个浮点数并存入二进制文件binary.dat中；从此二进制文件中读取该数据并计算其总和和平均值。

不知道哪里有问题，输出一直不对😭😭

#include<iostream>
#include<fstream>
#include<stdlib.h>
using namespace std;
void main()
{
    ofstream outfile("binary.dat", ios::binary);
    if (!outfile.is_open())
    {
        cout << "打开失败" << endl;
        exit(0);

    }
    double c[10], a[10], sum = 0, ave;
    cout << "输入十个数"<<endl;
    for (int i = 0; i <= 9; i++)
    {
        cin >> c[i];
        outfile << c[i];
    }
    outfile.close();
    ifstream infile("binary.dat", ios::binary);
    if (!infile)
    {
        cout << "打开错误";
        exit(1);
    }
    for (int i = 0; i <= 9; i++)
    {
        infile >> a[i];
        sum += a[i];
    }
    ave = sum / 10;
    cout << "总和为：" << sum << " " << "平均值为：" << ave << endl;

}

Answer 1

怎么个不对法？？？