代码

#include<iostream>
#include<cmath>
#include<cstdio>
using namespace std;
int const MAX_N=1e5+7;
main()
{
    int n;
    int arr[MAX_N],l,r,m;
    cin>>n;
    for(int i=0;i<n;i++)
        cin>>arr[i];
    l=max(arr[0],arr[n-1]);
    r=min(arr[0],arr[n-1]);
    if(n&1) printf("%d %d %d",l,arr[n/2],r);
    else if((arr[n/2-1]+arr[n/2])&1) printf("%d %.1lf %d",l,(arr[n/2-1]+arr[n/2])/2.0,r);
    else printf("%d %d %d",l,(arr[n/2-1]+arr[n/2])/2,r);
    return 0;
}

题解汇总
CCF-CSP认证历年题解