Java 计算 S=a+aa+aaa+...+aa...a 的值

import java.util.Scanner;

public class Main { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.print("请输入一个1-9的数字："); int num = scanner.nextInt(); int sum = 0; // 记录总和 int temp = num; // 记录每一项的值 for (int i = 1; i <= num; i++) { sum += temp; // 累加每一项的值 temp = temp * 10 + num; // 计算下一项的值 } System.out.println('s=' + sum); } }