题解 | 小红的完全二叉树构造

import java.util.*;

public class Main{
    static Scanner in = new Scanner(System.in);
    public static void main(String[] args){
        int n = in.nextInt();
        for(int i = 2; i <= n; i += 2) System.out.print(i + " ");
        for(int i = 1; i <= n; i += 2) System.out.print(i + " ");
    }
}