ccf csp 201903-1 小中大

#include<bits/stdc++.h>
using namespace std;

int main(){
	int n;
	cin >> n;
	int num[n];
	for(int i = 0; i < n; i++){
		cin >> num[i];
	}
	
	if(num[0] >= num[n - 1]){
		cout << num[0] << " ";
		if(n % 2 == 1){
			cout << num[n / 2];
		}else{
			double mid = (num[n / 2] + num[n / 2 - 1]) / 2.0;
			if(mid == floor(mid)){
				cout << mid;
			}else{
				cout << fixed << setprecision(1) << mid;
			}
		}
		cout << " " << num[n - 1] << endl;
	}else{
		cout << num[n - 1] << " ";
		if(n % 2 == 1){
			cout << num[n / 2];
		}else{
			double mid = (num[n / 2] + num[n / 2 - 1]) / 2.0;
			if(mid == floor(mid)){
				cout << mid;
			}else{
				cout << fixed << setprecision(1) << mid;
			}
		}
		cout << " " << num[0] << endl;
	}
	
	return 0;
}

不保证完全通过，仅测试了样例。