题解 | 尼科彻斯定理

import java.util.*;


// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        ArrayList<Integer> list = new ArrayList<>();
        int n = in.nextInt();
        int count = 0;
        for (int i = 1; i <= n; i++) {
            count += i;
        }
        int x = 1;
        for (int i = 0; i < count; i++) {
            list.add(x);
            x = x + 2;

        }
        for (int i = list.size() - n ; i < list.size(); i++) {
            if (i < list.size() - 1) {
                System.out.print(list.get(i) + "+");
            } else {
                System.out.print(list.get(i));
            }
        }

    }
}