vector应用，编程输入n个学生成绩，输出其平均值，c++程序设计

Question

#include <iostream>
#include <vector>
using namespace std;

//计算数组arr中元素的平均值
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int main() {
unsigned n;
cout << "n = ";
cin >> n;

vector<double> arr(n);//创建数组对象
cout << "Please input " << n << " real numbers:\n" ;
for (unsigned i = 0; i < n; i++)
cin >> arr[i];
cout<<"Output:";
cout << "Average = " << average(arr) <<"\n";
return 0;
}

在start和end之间填代码

Answer 1

double average(vector<double>& arr)
{
    double val = 0; 
    for(vector<double>::iterator it = arr.begin(); it != arr.end(); ++it)
    {
        val += *it; 
    }   
    val /= arr.size();
    return val;  
}