代码如下

#include<bits/stdc++.h>
using namespace std;
const int N = 100001;
int n;
int a[N];
double sum = 0;
int main(){
cin>>n;
for(int i = 0;i <= n - 1;i++){
cin>>a[i];
}
//遍历整个数组
for(int i = 0;i <= n - 1;i++){
sum = sum + a[i];//求和
}
printf("%.2lf",sum / n);
return 0;
}