题解 | #求平均年龄#

#include <iostream>
using namespace std;

const int N = 105;
int a[N];
int n;

int main()
{
    cin >> n;
    for (int i = 0; i < n; ++i)
        cin >> a[i];
    double res = 0.0;
    for (int i = 0; i < n; ++i)
        res += a[i];
    printf("%.2f", res / n);
    return 0;
}