东秦oj 求和again

思路：纯纯规律题 n=1 为55 n=2 为5050 n=3 为500500

需要注意输出格式必须要严格和其相同

import java.util.ArrayList;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        ArrayList<String> list = new ArrayList<>();
        while(!sc.hasNext("-1"))
        {
            int n = sc.nextInt();
            if (n==0) {
                list.add("1");
                continue;
            }
            list.add(powN(n));

        }
        for (String s : list) {
            System.out.println(s);
        }
    }

    public static String powN(int n)
    {
        String s = 5+"";
        while(n>1)
        {
            n--;
            s=s+"0";
        }
        return  s+s;
    }
}