Fata Morgana

#include <iostream>
#include <algorithm>
using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    int n;
    cin>>n;
    unsigned int v[n+1];
    v[0]=0;
    for(int i=1;i<=n;++i)
        cin>>v[i];
    sort(v,v+n+1);
    int j=1,a[n+1];
    for(int i=1;i<=n/2;++i)
        a[j++]=v[i],a[j++]=v[n/2+i];
    if(n%4!=0)
        swap(a[n-1],a[n]);
    bool ok=false;
    for(int i=1;i<=n;i+=2)
        if(a[i]==a[i+1])
            ok=true,i=n+1;
    if(ok)
        for(int i=1;i<=n;++i)
            cout<<v[i]<<' ';
    else
        for(int i=1;i<=n;++i)
            cout<<a[i]<<' ';
    return 0;
}