#include <stdio.h>
#include <math.h>
#include <iostream>
using namespace std;
int main()
{
	double n,sum = 0,x;
	cin >>n;
	for(int i = 0; i < n ; i++)
	{
		cin >> x;
		sum += x;
	}
	printf("%.2lf\n",sum/n);
}

/*********************************
备注:
*********************************/
#include <iostream>
#include <cstdio>
#include <iomanip>
#include <cmath>
#include <math.h>
#include <algorithm>
#include <cstring>
#include <string>
#include <stack>
#include <queue>
#include <algorithm>
#define LL long long
using namespace std;
const int INF = 0x3f3f3f3f;
const int N = 1e5 + 10;
double n , a[N] , m;
double b;
int main()
{
cin >> n;
for(int i = 1; i <= n; i++)
{
cin >> a[i];
}
for(int i = 1; i <= n; i++)
{
m = m + a[i];
}
b = m / n;
cout << fixed << setprecision(2) << b << endl;
return 0;
}

#include<iomanip>
#include <iostream>
using namespace std;
int main()
{
	double n,a,s=0,sum=0;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>a;
		s++;
		sum+=a;	
	}
	cout<<fixed<<setprecision(2)<<sum/s;
	return 0;
}

#include<iomanip> #include <iostream> using namespace std; int main() { double n,a,s=0,sum=0; cin>>n; for(int i=1;i<=n;i++) { cin>>a; s++; sum+=a; } cout<<fixed<<setprecision(2)<<sum/s; return 0; }

#include <bits/stdc++.h>//直接使用万能头
/*#include <iostream>
#include <stdio.h>
#include <stdbool.h>//要定义bool型变量必须要这个
#include <iomanip>
#include <cstdio>
*/
//保留小数位数代码:setiosflags(ios::fixed) << setprecision(保留小数位数) << 浮点数;
//数组排序：升序：sort(m,m + n);降序:sort(m,m + n, greater<int>());


//any function
void sleep(int p){
	long long int jiouiuiojioiouuiijyuiuyiyi = 0;
	const int N = 1e5 + 10;
	const int INF = 0x3f3f3f3f;
	for(int k = 1;k <= p;k++){
		for(int j = 1;j <= 300;j++){
			for(int i = 1;i <= N;i++){
			jiouiuiojioiouuiijyuiuyiyi += pow(N,N);
			}
		}
	}
}


//code write block
using namespace std;
const int N = 1e5 + 10;
const int INF = 0x3f3f3f3f;
int main(){
	int n,sum = 0,x;
	double ans;
	cin >> n;
	for(int i = 1;i <= n;i++){
		cin >> x;
		sum += x; 
	}
	ans = 1.0 * sum / n;
	cout << setiosflags(ios::fixed) << setprecision(2) << ans;
	return 0;
	}

请先理解代码

#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cctype>
#include<cstring>
#include<string>
#include<vector>
#include<set>
#include<stack>
#include<queue>
#include<iostream>
#include<iomanip>
#include<ctime>
#include<algorithm>
#include<map>
using namespace std;
int main(){
    int n;
    double sum=0.0;
    cin>>n;
    for(int i=1;i<=n;i++){
        int a;
        cin>>a;
        sum+=a;
    }
    // cout<<sum<<endl;
    printf("%.2f",sum/n);
}

hao

#include<bits/stdc++.h> using namespace std; int main() { int n,a[101],s=0; cin>>n; for(int i=1;i<=n;i++) { cin>>a[i]; s+=a[i]; } cout<<fixed<<setprecision(2)<<(double)s1.00/n1.00; return 0; }`````

#include<iostream>
#include<iomanip>
using namespace std;
int main(){
	double a,b,c;
	cin>>a;
	for(int i=1;i<=a;i++)
	{
		cin>>b;
		c+=b;
	}
	cout<<fixed<<setprecision(2)<<c/a<<endl;
}

 include <stdio.h>
#include <math.h>
#include <iostream>
using namespace std;
int main()
{
	double n,sum = 0,x;
	cin >>n;
	for(int i = 0; i < n ; i++)
	{
		cin >> x;
		sum += x;
	}
	printf("%.2lf\n",sum/n);
}

#include<iostream>
#include<iomanip>
#include<math.h>
using namespace std;
int main()
{
    int n;  
    cin >> n;
    double a,b,c;
    for (int i =1; i<=n;i++)
    {
        cin >>a;
        b+=a;
    }
    c=b/n;
    printf("%.2lf",c);
}

#include<iostream>
#include<iomanip>
#include<math.h>
using namespace std;
int main()
{
    int n;  
    cin >> n;
    double a,b,c;
    for (int i =1; i<=n;i++)
    {
        cin >>a;
        b+=a;
    }
    c=b/n;
    printf("%.2lf",c);
}

#include <stdio.h>
#include <iostream>
using namespace std;
int main()
{
	double n,sum = 0,x;
    cin >> n;
    for (int i = 0 ; i < n; i++)
    {
        cin >> x;
        sum += x;
    }
    printf("%.2lf\n",sum/n);
}

a