#include<bits/stdc++.h>
using namespace std;
int main()
{
    int n;
    double j = 0;
    cin>>n;
    for(int i = 1;i <= n;i++)
    {
        int x;
        cin>>x;
        j += x;
    }
    cout<<j<<" ";
    cout<<fixed<<setprecision(5)<<j / n;
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
	double a=0,b=0,c=0,n=0,x=0;
	int m=0;
	cin>>n;
	for(int i=1;i<=n;i++)
	{
		cin>>x;
		m=m+x;
	}
	b=m/n;
	cout<<m<<" ";
	cout<<fixed<<setprecision(5)<<b;
	
	
	return 0;
}

#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n;
	cin>>n;
	double cut;
	for(int i=1;i<=n;i++)
	{
		int x;
		cin>>x;
		cut+=x;
	}
	cout<<cut<<" "<<fixed<<setprecision(5)<<cut/n;
    return 0;
}

这题太难看

#include<bits/stdc++.h> using namespace std; int main() { int a; cin>>a; int s; double d=0; for (int i=1;i<=a;i++) { cin>>s; d+=s; } cout<<d<<" "; cout<<fixed<<setprecision(5)<<d/a; return 0; }