构造题

我们从中间开始取元素，然后左右来回取最近的元素，一定可以保证范围不断地变大

#include<iostream>
#include<algorithm>
using namespace std;
const int max_n = 1e5+100;
int a[max_n];
int n;

int main()
{
    ios::sync_with_stdio(0);
    cin>>n;
    for (int i=1;i<=n;++i)cin>>a[i];
    sort(a+1,a+1+n);
    int id1 = (n+1)/2;
    int id2 = id1+1;
    for (int i=1;i<=n;++i)
    {
        if (i&1)
        {
            cout<<a[id1]<<" ";
            --id1;
        }
        else 
        {
            cout<<a[id2]<<" ";
            ++id2;
        }
    }
    cout<<endl;
}