#include<iostream> using namespace std; int main(){ /** //int, long long, float, double, bool, char; int a[5] float[5]...... long long [5] != int[5] //我们班编程的成绩int a[11]={400,400,310,300,240,210,200,140,110,60,40}; for(int i=0;i<11;i++){ cout<<a[i]<<endl; } //数组的定义; int a[10]; //输入; for(int i=0;i<10;i++){ cin>>a[i]; } //输出; for(int i=9;i>=0;i--){ cout<<a[i]<<" "; } int a[10]; for(int i=0;i<10;i++){ cin>>a[i]; } int y,p=a[0]; for(int i=1;i<10;i++){ if(a[i]>p){ y=i; p=a[i]; } } cout<<y+1; int n; cin>>n; int a[n],b[n]; for(int i=0;i<n;i++){ cin>>a[i]; } for(int i=0;i<n;i++){ cin>>b[i]; } long long sum=0; for(int i=0;i<n;i++){ sum+=a[i]*b[i]; } cout<<sum; int n; cin>>n; int a[n]; for(int i=0;i<n;i++){ cin>>a[i]; } if(n%2!=0){ for(int i=0;i<n-1;i+=2){ int y; y=a[i]; a[i]=a[i+1]; a[i+1]=y; cout<<a[i]<<" "<<a[i+1]<<" "; } cout<<a[n-1]; }else{ for(int i=0;i<=n-1;i+=2){ int y; y=a[i]; a[i]=a[i+1]; a[i+1]=y; cout<<a[i]<<" "<<a[i+1]<<" "; } } int n; cin>>n; int a[n]; for(int i=0;i<n;i++){ cin>>a[i]; } int b[n]; for(int i=0;i<n;i++){ b[i]=a[a[i]-1]; } for(int i=0;i<n;i++){ cout<<a[b[i]-1]<<" "; } int n; cin>>n; int a[n]; for(int i=0;i<n;i++){ cin>>a[i]; } int u=a[0],y=a[0]; for(int i=1;i<n;i++){ if(u<a[i]){ u=a[i]; }else{ if(y>a[i]){ y=a[i]; } } } cout<<u-y; int n; cin>>n; int x[n]; cin>>x[0]>>x[1]>>x[2]>>x[3]; int p=x[0],y=x[0]; if(x[1]-x[0]==x[2]-x[1]){ for(int i=1;i<n;i++){ p=p+(x[2]-x[1]); } cout<<p; }else{ for(int i=1;i<n;i++){ y=y*x[2]/x[1]; } cout<<y; } int n; cin>>n; int a[n]; for(int i=0;i<n;i++){ cin>>a[i]; } int sum=0; for(int i=0;i<n;i++){ sum+=a[i]; } cout<<sum*4<<" "<<sum*2; int n; cin>>n; int a[n],x,c; for(int i=0;i<n;i++){ cin>>a[i]; } cin>>x>>c; a[x-1]=c; for(int i=0;i<n;i++){ cout<<a[i]<<" "; } int n; cin>>n; int a[n],m; for(int i=0;i<n;i++){ cin>>a[i]; } cin>>m; for(int i=0;i<n;i++){ if(a[i]>100){ a[i]=m; } } for(int i=0;i<n;i++){ cout<<a[i]<<" "; } **/ int n; cin>>n; float a[n],sum=0; for(int i=0;i<n;i++){ cin>>a[i]; sum+=a[i]; } printf("%.2lf",sum/n); return 0; }