题解 | #求平均年龄#

#include <stdio.h>

using namespace std;

int main () {
	int n;
	int arr[101];
	double sum = 0;
	double ave = 0;
	while (scanf ("%d", &n) != EOF){
		for (int i = 0; i < n; i++){
			scanf ("%d", &arr[i]);
			sum += arr[i];
			ave = sum / n;
		}
		printf ("%.2f", ave);
	}
	return 0;
}