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

主要要运用For循环，正确代码如下： #include<iostream> using namespace std; int main(){ int n,m; double sum; cin>>n; for(int i=1;i<=n;i++){ cin>>m; sum+=m; } printf("%.2f",sum/n); return 0; }

#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; }

n = int(input()) ages = list(map(int, input().split())) print("%.2f" % (sum(ages)/n))

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