题解

#include<bits/stdc++.h>
using namespace std;
int n,maxx,minn=99999999,a[100005];
int main(){
    cin>>n;
    for(int i=0;i<n;i++) cin>>a[i];
    for(int i=0;i<n;i++){
        int x;
        cin>>x;
        if(minn>=a[i]-x) minn=a[i]-x;
        if(maxx<=a[i]+x) maxx=a[i]+x;
    }
    printf("%.1lf",(minn+maxx)*1.0/2);
    return 0;
}