用Java求s=a+aa+aaa+.....+aaa...a的值

用Java求s=a+aa+aaa+…+aaa…a的值

package p3;

import java.util.Scanner;

public class samenumber {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		long a,b=0,sum=0;
		Scanner s=new Scanner(System.in);
		System.out.println("输入数字a的值:  ");
		a=s.nextInt();
		System.out.println("输入相加的项数:");
		int n=s.nextInt();
		int i=0;
		while(i<n){
			b=b+a;
			sum=sum+b;
			a=a*10;
			++i;
		}
		System.out.println(sum);
	}

}

运行截图