题解 | #尼科彻斯定理#

```import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            int n = sc.nextInt();
            int m = n * n * n;
            ArrayList<Integer> list = new ArrayList<>();
            if(n == 1){
                System.out.println("1");
                continue;
            }
            for (int i = n / 2; i > 0; i--) {
                if (n % 2 == 0) {
                    list.add(n * n - 1 - 2 * (i - 1));
                    list.add(n * n + 1 + 2 * (i - 1));
                } else {
                    if (i == 1) {
                        list.add(n * n);
                    }
                    list.add(n * n - 2 * i);
                    list.add(n * n + 2 * i);
                }
            }
            Collections.sort(list);
            for (int i = 0; i < list.size(); i++) {
                if (i == list.size() - 1) {
                    System.out.println(list.get(i));
                } else {
                    System.out.print(list.get(i) + "+");
                }
            }
        }
    }
}