用动态内存管理,求算数平均值

#include<iostream>
using namespace std;
int main()
{
	//使用动态内存分配求平均值:
	int n = 0;
	cout << "需要求的数字总个数:>" << endl;
	cin >> n;
	int* arr = new int[n];
    if(arr==NULL)
    {
        cout<<"内存开辟失败"<<endl;
        exit(1);
    }
	cout << "请输入"<<n<<"个数据:>" << endl;
	for (int i = 0; i < n; i++)
	{
		cin >> arr[i];
	}
	double sum = 0;
	for (int i = 0; i < n; i++)
	{
		sum += arr[i];
	}
	cout << "算数平均值为:" << (double)sum / n << endl;

	delete[]arr;
	arr = NULL;
	return 0;
}